Replace 'ERR_EXPLAIN' with 'ERR_FAIL_*_MSG' in 'core/' and 'editor/'

Condensed some if and ERR statements. Added dots to end of error messages

Couldn't figure out EXPLAINC. These files gave me trouble: core/error_macros.h, core/io/file_access_buffered_fa.h (where is it?),
core/os/memory.cpp,
drivers/png/png_driver_common.cpp,
drivers/xaudio2/audio_driver_xaudio2.cpp (where is it?)

14 files changed, 112 insertions, 244 deletions

diff --git a/core/io/config_file.cpp b/core/io/config_file.cpp
index f7fb72c089..70bb816acd 100644
--- a/core/io/config_file.cpp
+++ b/core/io/config_file.cpp
@@ -86,10 +86,7 @@ void ConfigFile::set_value(const String &p_section, const String &p_key, const V
 Variant ConfigFile::get_value(const String &p_section, const String &p_key, Variant p_default) const {
 
 	if (!values.has(p_section) || !values[p_section].has(p_key)) {
-		if (p_default.get_type() == Variant::NIL) {
-			ERR_EXPLAIN("Couldn't find the given section/key and no default was given");
-			ERR_FAIL_V(p_default);
-		}
+		ERR_FAIL_COND_V_MSG(p_default.get_type() == Variant::NIL, p_default, "Couldn't find the given section/key and no default was given.");
 		return p_default;
 	}
 	return values[p_section][p_key];
@@ -271,7 +268,7 @@ Error ConfigFile::_internal_load(const String &p_path, FileAccess *f) {
 			memdelete(f);
 			return OK;
 		} else if (err != OK) {
-			ERR_PRINTS("ConfgFile::load - " + p_path + ":" + itos(lines) + " error: " + error_text);
+			ERR_PRINTS("ConfgFile::load - " + p_path + ":" + itos(lines) + " error: " + error_text + ".");
 			memdelete(f);
 			return err;
 		}
diff --git a/core/io/file_access_buffered.cpp b/core/io/file_access_buffered.cpp
index 15523a49a9..f72ad61da6 100644
--- a/core/io/file_access_buffered.cpp
+++ b/core/io/file_access_buffered.cpp
@@ -87,10 +87,8 @@ bool FileAccessBuffered::eof_reached() const {
 }
 
 uint8_t FileAccessBuffered::get_8() const {
-	if (!file.open) {
-		ERR_EXPLAIN("Can't get data, when file is not opened.");
-		ERR_FAIL_V(0);
-	}
+
+	ERR_FAIL_COND_V_MSG(!file.open, 0, "Can't get data, when file is not opened.");
 
 	uint8_t byte = 0;
 	if (cache_data_left() >= 1) {
@@ -104,10 +102,8 @@ uint8_t FileAccessBuffered::get_8() const {
 }
 
 int FileAccessBuffered::get_buffer(uint8_t *p_dest, int p_length) const {
-	if (!file.open) {
-		ERR_EXPLAIN("Can't get buffer, when file is not opened.");
-		ERR_FAIL_V(-1);
-	}
+
+	ERR_FAIL_COND_V_MSG(!file.open, -1, "Can't get buffer, when file is not opened.");
 
 	if (p_length > cache_size) {
 
diff --git a/core/io/file_access_encrypted.cpp b/core/io/file_access_encrypted.cpp
index ccee6aeb15..1452c61d1a 100644
--- a/core/io/file_access_encrypted.cpp
+++ b/core/io/file_access_encrypted.cpp
@@ -94,8 +94,7 @@ Error FileAccessEncrypted::open_and_parse(FileAccess *p_base, const Vector<uint8
 		unsigned char hash[16];
 		ERR_FAIL_COND_V(CryptoCore::md5(data.ptr(), data.size(), hash) != OK, ERR_BUG);
 
-		ERR_EXPLAIN("The MD5 sum of the decrypted file does not match the expected value. It could be that the file is corrupt, or that the provided decryption key is invalid.");
-		ERR_FAIL_COND_V(String::md5(hash) != String::md5(md5d), ERR_FILE_CORRUPT);
+		ERR_FAIL_COND_V_MSG(String::md5(hash) != String::md5(md5d), ERR_FILE_CORRUPT, "The MD5 sum of the decrypted file does not match the expected value. It could be that the file is corrupt, or that the provided decryption key is invalid.");
 
 		file = p_base;
 	}
@@ -298,7 +297,7 @@ uint32_t FileAccessEncrypted::_get_unix_permissions(const String &p_file) {
 }
 
 Error FileAccessEncrypted::_set_unix_permissions(const String &p_file, uint32_t p_permissions) {
-	ERR_PRINT("Setting UNIX permissions on encrypted files is not implemented yet");
+	ERR_PRINT("Setting UNIX permissions on encrypted files is not implemented yet.");
 	return ERR_UNAVAILABLE;
 }
 
diff --git a/core/io/file_access_pack.cpp b/core/io/file_access_pack.cpp
index ca66b34e17..6b683759f8 100644
--- a/core/io/file_access_pack.cpp
+++ b/core/io/file_access_pack.cpp
@@ -171,10 +171,8 @@ bool PackedSourcePCK::try_open_pack(const String &p_path) {
 	uint32_t ver_minor = f->get_32();
 	f->get_32(); // ver_rev
 
-	ERR_EXPLAIN("Pack version unsupported: " + itos(version));
-	ERR_FAIL_COND_V(version != PACK_VERSION, false);
-	ERR_EXPLAIN("Pack created with a newer version of the engine: " + itos(ver_major) + "." + itos(ver_minor));
-	ERR_FAIL_COND_V(ver_major > VERSION_MAJOR || (ver_major == VERSION_MAJOR && ver_minor > VERSION_MINOR), false);
+	ERR_FAIL_COND_V_MSG(version != PACK_VERSION, false, "Pack version unsupported: " + itos(version) + ".");
+	ERR_FAIL_COND_V_MSG(ver_major > VERSION_MAJOR || (ver_major == VERSION_MAJOR && ver_minor > VERSION_MINOR), false, "Pack created with a newer version of the engine: " + itos(ver_major) + "." + itos(ver_minor) + ".");
 
 	for (int i = 0; i < 16; i++) {
 		//reserved
@@ -322,10 +320,9 @@ bool FileAccessPack::file_exists(const String &p_name) {
 FileAccessPack::FileAccessPack(const String &p_path, const PackedData::PackedFile &p_file) :
 		pf(p_file),
 		f(FileAccess::open(pf.pack, FileAccess::READ)) {
-	if (!f) {
-		ERR_EXPLAIN("Can't open pack-referenced file: " + String(pf.pack));
-		ERR_FAIL_COND(!f);
-	}
+
+	ERR_FAIL_COND_MSG(!f, "Can't open pack-referenced file: " + String(pf.pack) + ".");
+
 	f->seek(pf.offset);
 	pos = 0;
 	eof = false;
diff --git a/core/io/ip_address.cpp b/core/io/ip_address.cpp
index 9305afac5f..df4be9b9fd 100644
--- a/core/io/ip_address.cpp
+++ b/core/io/ip_address.cpp
@@ -81,8 +81,7 @@ static void _parse_hex(const String &p_string, int p_start, uint8_t *p_dst) {
 		} else if (c == ':') {
 			break;
 		} else {
-			ERR_EXPLAIN("Invalid character in ipv6 address: " + p_string);
-			ERR_FAIL();
+			ERR_FAIL_MSG("Invalid character in IPv6 address: " + p_string + ".");
 		};
 		ret = ret << 4;
 		ret += n;
@@ -126,9 +125,7 @@ void IP_Address::_parse_ipv6(const String &p_string) {
 				++parts_count;
 			};
 		} else {
-
-			ERR_EXPLAIN("Invalid character in IPv6 address: " + p_string);
-			ERR_FAIL();
+			ERR_FAIL_MSG("Invalid character in IPv6 address: " + p_string + ".");
 		};
 	};
 
@@ -166,10 +163,7 @@ void IP_Address::_parse_ipv4(const String &p_string, int p_start, uint8_t *p_ret
 	};
 
 	int slices = ip.get_slice_count(".");
-	if (slices != 4) {
-		ERR_EXPLAIN("Invalid IP Address String: " + ip);
-		ERR_FAIL();
-	}
+	ERR_FAIL_COND_MSG(slices != 4, "Invalid IP address string: " + ip + ".");
 	for (int i = 0; i < 4; i++) {
 		p_ret[i] = ip.get_slicec('.', i).to_int();
 	}
@@ -229,7 +223,7 @@ IP_Address::IP_Address(const String &p_string) {
 		valid = true;
 
 	} else {
-		ERR_PRINT("Invalid IP address");
+		ERR_PRINT("Invalid IP address.");
 	}
 }
 
diff --git a/core/io/marshalls.cpp b/core/io/marshalls.cpp
index dc5581ea01..b386feb14c 100644
--- a/core/io/marshalls.cpp
+++ b/core/io/marshalls.cpp
@@ -377,11 +377,6 @@ Error decode_variant(Variant &r_variant, const uint8_t *p_buffer, int p_len, int
 			}
 
 		} break;
-		/*case Variant::RESOURCE: {
-
-			ERR_EXPLAIN("Can't marshallize resources");
-			ERR_FAIL_V(ERR_INVALID_DATA); //no, i'm sorry, no go
-		} break;*/
 		case Variant::_RID: {
 
 			r_variant = RID();
@@ -1066,11 +1061,6 @@ Error encode_variant(const Variant &p_variant, uint8_t *r_buffer, int &r_len, bo
 			r_len += 4 * 4;
 
 		} break;
-		/*case Variant::RESOURCE: {
-
-			ERR_EXPLAIN("Can't marshallize resources");
-			ERR_FAIL_V(ERR_INVALID_DATA); //no, i'm sorry, no go
-		} break;*/
 		case Variant::_RID: {
 
 		} break;
diff --git a/core/io/multiplayer_api.cpp b/core/io/multiplayer_api.cpp
index 33dc4dbde4..d20133642b 100644
--- a/core/io/multiplayer_api.cpp
+++ b/core/io/multiplayer_api.cpp
@@ -146,8 +146,7 @@ void MultiplayerAPI::set_network_peer(const Ref<NetworkedMultiplayerPeer> &p_pee
 
 	network_peer = p_peer;
 
-	ERR_EXPLAIN("Supplied NetworkedNetworkPeer must be connecting or connected.");
-	ERR_FAIL_COND(p_peer.is_valid() && p_peer->get_connection_status() == NetworkedMultiplayerPeer::CONNECTION_DISCONNECTED);
+	ERR_FAIL_COND_MSG(p_peer.is_valid() && p_peer->get_connection_status() == NetworkedMultiplayerPeer::CONNECTION_DISCONNECTED, "Supplied NetworkedNetworkPeer must be connecting or connected.");
 
 	if (network_peer.is_valid()) {
 		network_peer->connect("peer_connected", this, "_add_peer");
@@ -164,10 +163,8 @@ Ref<NetworkedMultiplayerPeer> MultiplayerAPI::get_network_peer() const {
 
 void MultiplayerAPI::_process_packet(int p_from, const uint8_t *p_packet, int p_packet_len) {
 
-	ERR_EXPLAIN("Multiplayer root node was not initialized. If you are using custom multiplayer, remember to set the root node via MultiplayerAPI.set_root_node before using it");
-	ERR_FAIL_COND(root_node == NULL);
-	ERR_EXPLAIN("Invalid packet received. Size too small.");
-	ERR_FAIL_COND(p_packet_len < 1);
+	ERR_FAIL_COND_MSG(root_node == NULL, "Multiplayer root node was not initialized. If you are using custom multiplayer, remember to set the root node via MultiplayerAPI.set_root_node before using it.");
+	ERR_FAIL_COND_MSG(p_packet_len < 1, "Invalid packet received. Size too small.");
 
 	uint8_t packet_type = p_packet[0];
 
@@ -186,13 +183,11 @@ void MultiplayerAPI::_process_packet(int p_from, const uint8_t *p_packet, int p_
 		case NETWORK_COMMAND_REMOTE_CALL:
 		case NETWORK_COMMAND_REMOTE_SET: {
 
-			ERR_EXPLAIN("Invalid packet received. Size too small.");
-			ERR_FAIL_COND(p_packet_len < 6);
+			ERR_FAIL_COND_MSG(p_packet_len < 6, "Invalid packet received. Size too small.");
 
 			Node *node = _process_get_node(p_from, p_packet, p_packet_len);
 
-			ERR_EXPLAIN("Invalid packet received. Requested node was not found.");
-			ERR_FAIL_COND(node == NULL);
+			ERR_FAIL_COND_MSG(node == NULL, "Invalid packet received. Requested node was not found.");
 
 			// Detect cstring end.
 			int len_end = 5;
@@ -202,8 +197,7 @@ void MultiplayerAPI::_process_packet(int p_from, const uint8_t *p_packet, int p_
 				}
 			}
 
-			ERR_EXPLAIN("Invalid packet received. Size too small.");
-			ERR_FAIL_COND(len_end >= p_packet_len);
+			ERR_FAIL_COND_MSG(len_end >= p_packet_len, "Invalid packet received. Size too small.");
 
 			StringName name = String::utf8((const char *)&p_packet[5]);
 
@@ -235,8 +229,7 @@ Node *MultiplayerAPI::_process_get_node(int p_from, const uint8_t *p_packet, int
 
 		int ofs = target & 0x7FFFFFFF;
 
-		ERR_EXPLAIN("Invalid packet received. Size smaller than declared.");
-		ERR_FAIL_COND_V(ofs >= p_packet_len, NULL);
+		ERR_FAIL_COND_V_MSG(ofs >= p_packet_len, NULL, "Invalid packet received. Size smaller than declared.");
 
 		String paths;
 		paths.parse_utf8((const char *)&p_packet[ofs], p_packet_len - ofs);
@@ -246,33 +239,30 @@ Node *MultiplayerAPI::_process_get_node(int p_from, const uint8_t *p_packet, int
 		node = root_node->get_node(np);
 
 		if (!node)
-			ERR_PRINTS("Failed to get path from RPC: " + String(np));
+			ERR_PRINTS("Failed to get path from RPC: " + String(np) + ".");
 	} else {
 		// Use cached path.
 		int id = target;
 
 		Map<int, PathGetCache>::Element *E = path_get_cache.find(p_from);
-		ERR_EXPLAIN("Invalid packet received. Requests invalid peer cache.");
-		ERR_FAIL_COND_V(!E, NULL);
+		ERR_FAIL_COND_V_MSG(!E, NULL, "Invalid packet received. Requests invalid peer cache.");
 
 		Map<int, PathGetCache::NodeInfo>::Element *F = E->get().nodes.find(id);
-		ERR_EXPLAIN("Invalid packet received. Unabled to find requested cached node.");
-		ERR_FAIL_COND_V(!F, NULL);
+		ERR_FAIL_COND_V_MSG(!F, NULL, "Invalid packet received. Unabled to find requested cached node.");
 
 		PathGetCache::NodeInfo *ni = &F->get();
 		// Do proper caching later.
 
 		node = root_node->get_node(ni->path);
 		if (!node)
-			ERR_PRINTS("Failed to get cached path from RPC: " + String(ni->path));
+			ERR_PRINTS("Failed to get cached path from RPC: " + String(ni->path) + ".");
 	}
 	return node;
 }
 
 void MultiplayerAPI::_process_rpc(Node *p_node, const StringName &p_name, int p_from, const uint8_t *p_packet, int p_packet_len, int p_offset) {
 
-	ERR_EXPLAIN("Invalid packet received. Size too small.");
-	ERR_FAIL_COND(p_offset >= p_packet_len);
+	ERR_FAIL_COND_MSG(p_offset >= p_packet_len, "Invalid packet received. Size too small.");
 
 	// Check that remote can call the RPC on this node.
 	RPCMode rpc_mode = RPC_MODE_DISABLED;
@@ -284,8 +274,7 @@ void MultiplayerAPI::_process_rpc(Node *p_node, const StringName &p_name, int p_
 	}
 
 	bool can_call = _can_call_mode(p_node, rpc_mode, p_from);
-	ERR_EXPLAIN("RPC '" + String(p_name) + "' is not allowed on node " + p_node->get_path() + " from: " + itos(p_from) + ". Mode is " + itos((int)rpc_mode) + ", master is " + itos(p_node->get_network_master()) + ".");
-	ERR_FAIL_COND(!can_call);
+	ERR_FAIL_COND_MSG(!can_call, "RPC '" + String(p_name) + "' is not allowed on node " + p_node->get_path() + " from: " + itos(p_from) + ". Mode is " + itos((int)rpc_mode) + ", master is " + itos(p_node->get_network_master()) + ".");
 
 	int argc = p_packet[p_offset];
 	Vector<Variant> args;
@@ -297,13 +286,11 @@ void MultiplayerAPI::_process_rpc(Node *p_node, const StringName &p_name, int p_
 
 	for (int i = 0; i < argc; i++) {
 
-		ERR_EXPLAIN("Invalid packet received. Size too small.");
-		ERR_FAIL_COND(p_offset >= p_packet_len);
+		ERR_FAIL_COND_MSG(p_offset >= p_packet_len, "Invalid packet received. Size too small.");
 
 		int vlen;
 		Error err = decode_variant(args.write[i], &p_packet[p_offset], p_packet_len - p_offset, &vlen, allow_object_decoding || network_peer->is_object_decoding_allowed());
-		ERR_EXPLAIN("Invalid packet received. Unable to decode RPC argument.");
-		ERR_FAIL_COND(err != OK);
+		ERR_FAIL_COND_MSG(err != OK, "Invalid packet received. Unable to decode RPC argument.");
 
 		argp.write[i] = &args[i];
 		p_offset += vlen;
@@ -321,8 +308,7 @@ void MultiplayerAPI::_process_rpc(Node *p_node, const StringName &p_name, int p_
 
 void MultiplayerAPI::_process_rset(Node *p_node, const StringName &p_name, int p_from, const uint8_t *p_packet, int p_packet_len, int p_offset) {
 
-	ERR_EXPLAIN("Invalid packet received. Size too small.");
-	ERR_FAIL_COND(p_offset >= p_packet_len);
+	ERR_FAIL_COND_MSG(p_offset >= p_packet_len, "Invalid packet received. Size too small.");
 
 	// Check that remote can call the RSET on this node.
 	RPCMode rset_mode = RPC_MODE_DISABLED;
@@ -334,28 +320,25 @@ void MultiplayerAPI::_process_rset(Node *p_node, const StringName &p_name, int p
 	}
 
 	bool can_call = _can_call_mode(p_node, rset_mode, p_from);
-	ERR_EXPLAIN("RSET '" + String(p_name) + "' is not allowed on node " + p_node->get_path() + " from: " + itos(p_from) + ". Mode is " + itos((int)rset_mode) + ", master is " + itos(p_node->get_network_master()) + ".");
-	ERR_FAIL_COND(!can_call);
+	ERR_FAIL_COND_MSG(!can_call, "RSET '" + String(p_name) + "' is not allowed on node " + p_node->get_path() + " from: " + itos(p_from) + ". Mode is " + itos((int)rset_mode) + ", master is " + itos(p_node->get_network_master()) + ".");
 
 	Variant value;
 	Error err = decode_variant(value, &p_packet[p_offset], p_packet_len - p_offset, NULL, allow_object_decoding || network_peer->is_object_decoding_allowed());
 
-	ERR_EXPLAIN("Invalid packet received. Unable to decode RSET value.");
-	ERR_FAIL_COND(err != OK);
+	ERR_FAIL_COND_MSG(err != OK, "Invalid packet received. Unable to decode RSET value.");
 
 	bool valid;
 
 	p_node->set(p_name, value, &valid);
 	if (!valid) {
-		String error = "Error setting remote property '" + String(p_name) + "', not found in object of type " + p_node->get_class();
+		String error = "Error setting remote property '" + String(p_name) + "', not found in object of type " + p_node->get_class() + ".";
 		ERR_PRINTS(error);
 	}
 }
 
 void MultiplayerAPI::_process_simplify_path(int p_from, const uint8_t *p_packet, int p_packet_len) {
 
-	ERR_EXPLAIN("Invalid packet received. Size too small.");
-	ERR_FAIL_COND(p_packet_len < 5);
+	ERR_FAIL_COND_MSG(p_packet_len < 5, "Invalid packet received. Size too small.");
 	int id = decode_uint32(&p_packet[1]);
 
 	String paths;
@@ -390,8 +373,7 @@ void MultiplayerAPI::_process_simplify_path(int p_from, const uint8_t *p_packet,
 
 void MultiplayerAPI::_process_confirm_path(int p_from, const uint8_t *p_packet, int p_packet_len) {
 
-	ERR_EXPLAIN("Invalid packet received. Size too small.");
-	ERR_FAIL_COND(p_packet_len < 2);
+	ERR_FAIL_COND_MSG(p_packet_len < 2, "Invalid packet received. Size too small.");
 
 	String paths;
 	paths.parse_utf8((const char *)&p_packet[1], p_packet_len - 1);
@@ -399,12 +381,10 @@ void MultiplayerAPI::_process_confirm_path(int p_from, const uint8_t *p_packet,
 	NodePath path = paths;
 
 	PathSentCache *psc = path_send_cache.getptr(path);
-	ERR_EXPLAIN("Invalid packet received. Tries to confirm a path which was not found in cache.");
-	ERR_FAIL_COND(!psc);
+	ERR_FAIL_COND_MSG(!psc, "Invalid packet received. Tries to confirm a path which was not found in cache.");
 
 	Map<int, bool>::Element *E = psc->confirmed_peers.find(p_from);
-	ERR_EXPLAIN("Invalid packet received. Source peer was not found in cache for the given path.");
-	ERR_FAIL_COND(!E);
+	ERR_FAIL_COND_MSG(!E, "Invalid packet received. Source peer was not found in cache for the given path.");
 	E->get() = true;
 }
 
@@ -460,39 +440,22 @@ bool MultiplayerAPI::_send_confirm_path(NodePath p_path, PathSentCache *psc, int
 
 void MultiplayerAPI::_send_rpc(Node *p_from, int p_to, bool p_unreliable, bool p_set, const StringName &p_name, const Variant **p_arg, int p_argcount) {
 
-	if (network_peer.is_null()) {
-		ERR_EXPLAIN("Attempt to remote call/set when networking is not active in SceneTree.");
-		ERR_FAIL();
-	}
+	ERR_FAIL_COND_MSG(network_peer.is_null(), "Attempt to remote call/set when networking is not active in SceneTree.");
 
-	if (network_peer->get_connection_status() == NetworkedMultiplayerPeer::CONNECTION_CONNECTING) {
-		ERR_EXPLAIN("Attempt to remote call/set when networking is not connected yet in SceneTree.");
-		ERR_FAIL();
-	}
+	ERR_FAIL_COND_MSG(network_peer->get_connection_status() == NetworkedMultiplayerPeer::CONNECTION_CONNECTING, "Attempt to remote call/set when networking is not connected yet in SceneTree.");
 
-	if (network_peer->get_connection_status() == NetworkedMultiplayerPeer::CONNECTION_DISCONNECTED) {
-		ERR_EXPLAIN("Attempt to remote call/set when networking is disconnected.");
-		ERR_FAIL();
-	}
+	ERR_FAIL_COND_MSG(network_peer->get_connection_status() == NetworkedMultiplayerPeer::CONNECTION_DISCONNECTED, "Attempt to remote call/set when networking is disconnected.");
 
-	if (p_argcount > 255) {
-		ERR_EXPLAIN("Too many arguments >255.");
-		ERR_FAIL();
-	}
+	ERR_FAIL_COND_MSG(p_argcount > 255, "Too many arguments >255.");
 
 	if (p_to != 0 && !connected_peers.has(ABS(p_to))) {
-		if (p_to == network_peer->get_unique_id()) {
-			ERR_EXPLAIN("Attempt to remote call/set yourself! unique ID: " + itos(network_peer->get_unique_id()));
-		} else {
-			ERR_EXPLAIN("Attempt to remote call unexisting ID: " + itos(p_to));
-		}
+		ERR_FAIL_COND_MSG(p_to == network_peer->get_unique_id(), "Attempt to remote call/set yourself! unique ID: " + itos(network_peer->get_unique_id()) + ".");
 
-		ERR_FAIL();
+		ERR_FAIL_MSG("Attempt to remote call unexisting ID: " + itos(p_to) + ".");
 	}
 
 	NodePath from_path = (root_node->get_path()).rel_path_to(p_from->get_path());
-	ERR_EXPLAIN("Unable to send RPC. Relative path is empty. THIS IS LIKELY A BUG IN THE ENGINE!");
-	ERR_FAIL_COND(from_path.is_empty());
+	ERR_FAIL_COND_MSG(from_path.is_empty(), "Unable to send RPC. Relative path is empty. THIS IS LIKELY A BUG IN THE ENGINE!");
 
 	// See if the path is cached.
 	PathSentCache *psc = path_send_cache.getptr(from_path);
@@ -530,8 +493,7 @@ void MultiplayerAPI::_send_rpc(Node *p_from, int p_to, bool p_unreliable, bool p
 	if (p_set) {
 		// Set argument.
 		Error err = encode_variant(*p_arg[0], NULL, len, allow_object_decoding || network_peer->is_object_decoding_allowed());
-		ERR_EXPLAIN("Unable to encode RSET value. THIS IS LIKELY A BUG IN THE ENGINE!");
-		ERR_FAIL_COND(err != OK);
+		ERR_FAIL_COND_MSG(err != OK, "Unable to encode RSET value. THIS IS LIKELY A BUG IN THE ENGINE!");
 		MAKE_ROOM(ofs + len);
 		encode_variant(*p_arg[0], &(packet_cache.write[ofs]), len, allow_object_decoding || network_peer->is_object_decoding_allowed());
 		ofs += len;
@@ -543,8 +505,7 @@ void MultiplayerAPI::_send_rpc(Node *p_from, int p_to, bool p_unreliable, bool p
 		ofs += 1;
 		for (int i = 0; i < p_argcount; i++) {
 			Error err = encode_variant(*p_arg[i], NULL, len, allow_object_decoding || network_peer->is_object_decoding_allowed());
-			ERR_EXPLAIN("Unable to encode RPC argument. THIS IS LIKELY A BUG IN THE ENGINE!");
-			ERR_FAIL_COND(err != OK);
+			ERR_FAIL_COND_MSG(err != OK, "Unable to encode RPC argument. THIS IS LIKELY A BUG IN THE ENGINE!");
 			MAKE_ROOM(ofs + len);
 			encode_variant(*p_arg[i], &(packet_cache.write[ofs]), len, allow_object_decoding || network_peer->is_object_decoding_allowed());
 			ofs += len;
@@ -626,12 +587,9 @@ void MultiplayerAPI::_server_disconnected() {
 
 void MultiplayerAPI::rpcp(Node *p_node, int p_peer_id, bool p_unreliable, const StringName &p_method, const Variant **p_arg, int p_argcount) {
 
-	ERR_EXPLAIN("Trying to call an RPC while no network peer is active.");
-	ERR_FAIL_COND(!network_peer.is_valid());
-	ERR_EXPLAIN("Trying to call an RPC on a node which is not inside SceneTree.");
-	ERR_FAIL_COND(!p_node->is_inside_tree());
-	ERR_EXPLAIN("Trying to call an RPC via a network peer which is not connected.");
-	ERR_FAIL_COND(network_peer->get_connection_status() != NetworkedMultiplayerPeer::CONNECTION_CONNECTED);
+	ERR_FAIL_COND_MSG(!network_peer.is_valid(), "Trying to call an RPC while no network peer is active.");
+	ERR_FAIL_COND_MSG(!p_node->is_inside_tree(), "Trying to call an RPC on a node which is not inside SceneTree.");
+	ERR_FAIL_COND_MSG(network_peer->get_connection_status() != NetworkedMultiplayerPeer::CONNECTION_CONNECTED, "Trying to call an RPC via a network peer which is not connected.");
 
 	int node_id = network_peer->get_unique_id();
 	bool skip_rpc = node_id == p_peer_id;
@@ -668,7 +626,7 @@ void MultiplayerAPI::rpcp(Node *p_node, int p_peer_id, bool p_unreliable, const
 		rpc_sender_id = temp_id;
 		if (ce.error != Variant::CallError::CALL_OK) {
 			String error = Variant::get_call_error_text(p_node, p_method, p_arg, p_argcount, ce);
-			error = "rpc() aborted in local call:  - " + error;
+			error = "rpc() aborted in local call:  - " + error + ".";
 			ERR_PRINTS(error);
 			return;
 		}
@@ -683,24 +641,20 @@ void MultiplayerAPI::rpcp(Node *p_node, int p_peer_id, bool p_unreliable, const
 		rpc_sender_id = temp_id;
 		if (ce.error != Variant::CallError::CALL_OK) {
 			String error = Variant::get_call_error_text(p_node, p_method, p_arg, p_argcount, ce);
-			error = "rpc() aborted in script local call:  - " + error;
+			error = "rpc() aborted in script local call:  - " + error + ".";
 			ERR_PRINTS(error);
 			return;
 		}
 	}
 
-	ERR_EXPLAIN("RPC '" + p_method + "' on yourself is not allowed by selected mode");
-	ERR_FAIL_COND(skip_rpc && !(call_local_native || call_local_script));
+	ERR_FAIL_COND_MSG(skip_rpc && !(call_local_native || call_local_script), "RPC '" + p_method + "' on yourself is not allowed by selected mode.");
 }
 
 void MultiplayerAPI::rsetp(Node *p_node, int p_peer_id, bool p_unreliable, const StringName &p_property, const Variant &p_value) {
 
-	ERR_EXPLAIN("Trying to RSET while no network peer is active.");
-	ERR_FAIL_COND(!network_peer.is_valid());
-	ERR_EXPLAIN("Trying to RSET on a node which is not inside SceneTree.");
-	ERR_FAIL_COND(!p_node->is_inside_tree());
-	ERR_EXPLAIN("Trying to send an RSET via a network peer which is not connected.");
-	ERR_FAIL_COND(network_peer->get_connection_status() != NetworkedMultiplayerPeer::CONNECTION_CONNECTED);
+	ERR_FAIL_COND_MSG(!network_peer.is_valid(), "Trying to RSET while no network peer is active.");
+	ERR_FAIL_COND_MSG(!p_node->is_inside_tree(), "Trying to RSET on a node which is not inside SceneTree.");
+	ERR_FAIL_COND_MSG(network_peer->get_connection_status() != NetworkedMultiplayerPeer::CONNECTION_CONNECTED, "Trying to send an RSET via a network peer which is not connected.");
 
 	int node_id = network_peer->get_unique_id();
 	bool is_master = p_node->is_network_master();
@@ -724,7 +678,7 @@ void MultiplayerAPI::rsetp(Node *p_node, int p_peer_id, bool p_unreliable, const
 			rpc_sender_id = temp_id;
 
 			if (!valid) {
-				String error = "rset() aborted in local set, property not found:  - " + String(p_property);
+				String error = "rset() aborted in local set, property not found:  - " + String(p_property) + ".";
 				ERR_PRINTS(error);
 				return;
 			}
@@ -742,7 +696,7 @@ void MultiplayerAPI::rsetp(Node *p_node, int p_peer_id, bool p_unreliable, const
 				rpc_sender_id = temp_id;
 
 				if (!valid) {
-					String error = "rset() aborted in local script set, property not found:  - " + String(p_property);
+					String error = "rset() aborted in local script set, property not found:  - " + String(p_property) + ".";
 					ERR_PRINTS(error);
 					return;
 				}
@@ -751,8 +705,7 @@ void MultiplayerAPI::rsetp(Node *p_node, int p_peer_id, bool p_unreliable, const
 	}
 
 	if (skip_rset) {
-		ERR_EXPLAIN("RSET for '" + p_property + "' on yourself is not allowed by selected mode");
-		ERR_FAIL_COND(!set_local);
+		ERR_FAIL_COND_MSG(!set_local, "RSET for '" + p_property + "' on yourself is not allowed by selected mode.");
 		return;
 	}
 
@@ -763,12 +716,9 @@ void MultiplayerAPI::rsetp(Node *p_node, int p_peer_id, bool p_unreliable, const
 
 Error MultiplayerAPI::send_bytes(PoolVector<uint8_t> p_data, int p_to, NetworkedMultiplayerPeer::TransferMode p_mode) {
 
-	ERR_EXPLAIN("Trying to send an empty raw packet.");
-	ERR_FAIL_COND_V(p_data.size() < 1, ERR_INVALID_DATA);
-	ERR_EXPLAIN("Trying to send a raw packet while no network peer is active.");
-	ERR_FAIL_COND_V(!network_peer.is_valid(), ERR_UNCONFIGURED);
-	ERR_EXPLAIN("Trying to send a raw packet via a network peer which is not connected.");
-	ERR_FAIL_COND_V(network_peer->get_connection_status() != NetworkedMultiplayerPeer::CONNECTION_CONNECTED, ERR_UNCONFIGURED);
+	ERR_FAIL_COND_V_MSG(p_data.size() < 1, ERR_INVALID_DATA, "Trying to send an empty raw packet.");
+	ERR_FAIL_COND_V_MSG(!network_peer.is_valid(), ERR_UNCONFIGURED, "Trying to send a raw packet while no network peer is active.");
+	ERR_FAIL_COND_V_MSG(network_peer->get_connection_status() != NetworkedMultiplayerPeer::CONNECTION_CONNECTED, ERR_UNCONFIGURED, "Trying to send a raw packet via a network peer which is not connected.");
 
 	MAKE_ROOM(p_data.size() + 1);
 	PoolVector<uint8_t>::Read r = p_data.read();
@@ -783,8 +733,7 @@ Error MultiplayerAPI::send_bytes(PoolVector<uint8_t> p_data, int p_to, Networked
 
 void MultiplayerAPI::_process_raw(int p_from, const uint8_t *p_packet, int p_packet_len) {
 
-	ERR_EXPLAIN("Invalid packet received. Size too small.");
-	ERR_FAIL_COND(p_packet_len < 2);
+	ERR_FAIL_COND_MSG(p_packet_len < 2, "Invalid packet received. Size too small.");
 
 	PoolVector<uint8_t> out;
 	int len = p_packet_len - 1;
@@ -798,37 +747,32 @@ void MultiplayerAPI::_process_raw(int p_from, const uint8_t *p_packet, int p_pac
 
 int MultiplayerAPI::get_network_unique_id() const {
 
-	ERR_EXPLAIN("No network peer is assigned. Unable to get unique network ID.");
-	ERR_FAIL_COND_V(!network_peer.is_valid(), 0);
+	ERR_FAIL_COND_V_MSG(!network_peer.is_valid(), 0, "No network peer is assigned. Unable to get unique network ID.");
 	return network_peer->get_unique_id();
 }
 
 bool MultiplayerAPI::is_network_server() const {
 
 	// XXX Maybe fail silently? Maybe should actually return true to make development of both local and online multiplayer easier?
-	ERR_EXPLAIN("No network peer is assigned. I can't be a server.");
-	ERR_FAIL_COND_V(!network_peer.is_valid(), false);
+	ERR_FAIL_COND_V_MSG(!network_peer.is_valid(), false, "No network peer is assigned. I can't be a server.");
 	return network_peer->is_server();
 }
 
 void MultiplayerAPI::set_refuse_new_network_connections(bool p_refuse) {
 
-	ERR_EXPLAIN("No network peer is assigned. Unable to set 'refuse_new_connections'.");
-	ERR_FAIL_COND(!network_peer.is_valid());
+	ERR_FAIL_COND_MSG(!network_peer.is_valid(), "No network peer is assigned. Unable to set 'refuse_new_connections'.");
 	network_peer->set_refuse_new_connections(p_refuse);
 }
 
 bool MultiplayerAPI::is_refusing_new_network_connections() const {
 
-	ERR_EXPLAIN("No network peer is assigned. Unable to get 'refuse_new_connections'.");
-	ERR_FAIL_COND_V(!network_peer.is_valid(), false);
+	ERR_FAIL_COND_V_MSG(!network_peer.is_valid(), false, "No network peer is assigned. Unable to get 'refuse_new_connections'.");
 	return network_peer->is_refusing_new_connections();
 }
 
 Vector<int> MultiplayerAPI::get_network_connected_peers() const {
 
-	ERR_EXPLAIN("No network peer is assigned. Assume no peers are connected.");
-	ERR_FAIL_COND_V(!network_peer.is_valid(), Vector<int>());
+	ERR_FAIL_COND_V_MSG(!network_peer.is_valid(), Vector<int>(), "No network peer is assigned. Assume no peers are connected.");
 
 	Vector<int> ret;
 	for (Set<int>::Element *E = connected_peers.front(); E; E = E->next()) {
diff --git a/core/io/packet_peer.cpp b/core/io/packet_peer.cpp
index 1e4ea715b3..1c792c43d1 100644
--- a/core/io/packet_peer.cpp
+++ b/core/io/packet_peer.cpp
@@ -280,8 +280,7 @@ Ref<StreamPeer> PacketPeerStream::get_stream_peer() const {
 void PacketPeerStream::set_input_buffer_max_size(int p_max_size) {
 
 	//warning may lose packets
-	ERR_EXPLAIN("Buffer in use, resizing would cause loss of data");
-	ERR_FAIL_COND(ring_buffer.data_left());
+	ERR_FAIL_COND_MSG(ring_buffer.data_left(), "Buffer in use, resizing would cause loss of data.");
 	ring_buffer.resize(nearest_shift(p_max_size + 4));
 	input_buffer.resize(next_power_of_2(p_max_size + 4));
 }
diff --git a/core/io/pck_packer.cpp b/core/io/pck_packer.cpp
index c16d89d695..1c89bc6268 100644
--- a/core/io/pck_packer.cpp
+++ b/core/io/pck_packer.cpp
@@ -64,10 +64,7 @@ Error PCKPacker::pck_start(const String &p_file, int p_alignment) {
 
 	file = FileAccess::open(p_file, FileAccess::WRITE);
 
-	if (!file) {
-		ERR_EXPLAIN("Can't open file to write: " + String(p_file));
-		ERR_FAIL_V(ERR_CANT_CREATE);
-	}
+	ERR_FAIL_COND_V_MSG(!file, ERR_CANT_CREATE, "Can't open file to write: " + String(p_file) + ".");
 
 	alignment = p_alignment;
 
diff --git a/core/io/resource_format_binary.cpp b/core/io/resource_format_binary.cpp
index 146480e5a2..de10fe1376 100644
--- a/core/io/resource_format_binary.cpp
+++ b/core/io/resource_format_binary.cpp
@@ -490,8 +490,7 @@ Error ResourceInteractiveLoaderBinary::parse_variant(Variant &r_v) {
 #endif
 
 			} else {
-				ERR_EXPLAIN("Vector2 size is NOT 8!");
-				ERR_FAIL_V(ERR_UNAVAILABLE);
+				ERR_FAIL_V_MSG(ERR_UNAVAILABLE, "Vector2 size is NOT 8!");
 			}
 			w.release();
 			r_v = array;
@@ -518,8 +517,7 @@ Error ResourceInteractiveLoaderBinary::parse_variant(Variant &r_v) {
 #endif
 
 			} else {
-				ERR_EXPLAIN("Vector3 size is NOT 12!");
-				ERR_FAIL_V(ERR_UNAVAILABLE);
+				ERR_FAIL_V_MSG(ERR_UNAVAILABLE, "Vector3 size is NOT 12!");
 			}
 			w.release();
 			r_v = array;
@@ -546,8 +544,7 @@ Error ResourceInteractiveLoaderBinary::parse_variant(Variant &r_v) {
 #endif
 
 			} else {
-				ERR_EXPLAIN("Color size is NOT 16!");
-				ERR_FAIL_V(ERR_UNAVAILABLE);
+				ERR_FAIL_V_MSG(ERR_UNAVAILABLE, "Color size is NOT 16!");
 			}
 			w.release();
 			r_v = array;
@@ -571,7 +568,7 @@ Error ResourceInteractiveLoaderBinary::parse_variant(Variant &r_v) {
 				const uint32_t current_version = 0;
 				if (format_version > current_version) {
 
-					ERR_PRINT("Format version for encoded binary image is too new");
+					ERR_PRINT("Format version for encoded binary image is too new.");
 					return ERR_PARSE_ERROR;
 				}
 
@@ -655,8 +652,7 @@ Error ResourceInteractiveLoaderBinary::poll() {
 			} else {
 
 				error = ERR_FILE_MISSING_DEPENDENCIES;
-				ERR_EXPLAIN("Can't load dependency: " + path);
-				ERR_FAIL_V(error);
+				ERR_FAIL_V_MSG(error, "Can't load dependency: " + path + ".");
 			}
 
 		} else {
@@ -711,16 +707,15 @@ Error ResourceInteractiveLoaderBinary::poll() {
 	Object *obj = ClassDB::instance(t);
 	if (!obj) {
 		error = ERR_FILE_CORRUPT;
-		ERR_EXPLAIN(local_path + ":Resource of unrecognized type in file: " + t);
-		ERR_FAIL_V(ERR_FILE_CORRUPT);
+		ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, local_path + ":Resource of unrecognized type in file: " + t + ".");
 	}
 
 	Resource *r = Object::cast_to<Resource>(obj);
 	if (!r) {
+		String obj_class = obj->get_class();
 		error = ERR_FILE_CORRUPT;
-		ERR_EXPLAIN(local_path + ":Resource type in resource field not a resource, type is: " + obj->get_class());
 		memdelete(obj); //bye
-		ERR_FAIL_V(ERR_FILE_CORRUPT);
+		ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, local_path + ":Resource type in resource field not a resource, type is: " + obj_class + ".");
 	}
 
 	RES res = RES(r);
@@ -850,8 +845,7 @@ void ResourceInteractiveLoaderBinary::open(FileAccess *p_f) {
 		//not normal
 
 		error = ERR_FILE_UNRECOGNIZED;
-		ERR_EXPLAIN("Unrecognized binary resource file: " + local_path);
-		ERR_FAIL();
+		ERR_FAIL_MSG("Unrecognized binary resource file: " + local_path + ".");
 	}
 
 	bool big_endian = f->get_32();
@@ -877,8 +871,7 @@ void ResourceInteractiveLoaderBinary::open(FileAccess *p_f) {
 	if (ver_format > FORMAT_VERSION || ver_major > VERSION_MAJOR) {
 
 		f->close();
-		ERR_EXPLAIN("File Format '" + itos(FORMAT_VERSION) + "." + itos(ver_major) + "." + itos(ver_minor) + "' is too new! Please upgrade to a new engine version: " + local_path);
-		ERR_FAIL();
+		ERR_FAIL_MSG("File format '" + itos(FORMAT_VERSION) + "." + itos(ver_major) + "." + itos(ver_minor) + "' is too new! Please upgrade to a new engine version: " + local_path + ".");
 	}
 
 	type = get_unicode_string();
@@ -926,8 +919,7 @@ void ResourceInteractiveLoaderBinary::open(FileAccess *p_f) {
 	if (f->eof_reached()) {
 
 		error = ERR_FILE_CORRUPT;
-		ERR_EXPLAIN("Premature End Of File: " + local_path);
-		ERR_FAIL();
+		ERR_FAIL_MSG("Premature end of file (EOF): " + local_path + ".");
 	}
 }
 
@@ -1084,8 +1076,7 @@ Error ResourceFormatLoaderBinary::rename_dependencies(const String &p_path, cons
 
 		//error=ERR_FILE_UNRECOGNIZED;
 		memdelete(f);
-		ERR_EXPLAIN("Unrecognized binary resource file: " + local_path);
-		ERR_FAIL_V(ERR_FILE_UNRECOGNIZED);
+		ERR_FAIL_V_MSG(ERR_FILE_UNRECOGNIZED, "Unrecognized binary resource file: " + local_path + ".");
 	} else {
 		fw = FileAccess::open(p_path + ".depren", FileAccess::WRITE);
 		if (!fw) {
@@ -1122,7 +1113,7 @@ Error ResourceFormatLoaderBinary::rename_dependencies(const String &p_path, cons
 		memdelete(da);
 		//use the old approach
 
-		WARN_PRINT(("This file is old, so it can't refactor dependencies, opening and resaving: " + p_path).utf8().get_data());
+		WARN_PRINTS("This file is old, so it can't refactor dependencies, opening and resaving: " + p_path + ".");
 
 		Error err;
 		f = FileAccess::open(p_path, FileAccess::READ, &err);
@@ -1153,8 +1144,7 @@ Error ResourceFormatLoaderBinary::rename_dependencies(const String &p_path, cons
 
 		memdelete(f);
 		memdelete(fw);
-		ERR_EXPLAIN("File Format '" + itos(FORMAT_VERSION) + "." + itos(ver_major) + "." + itos(ver_minor) + "' is too new! Please upgrade to a new engine version: " + local_path);
-		ERR_FAIL_V(ERR_FILE_UNRECOGNIZED);
+		ERR_FAIL_V_MSG(ERR_FILE_UNRECOGNIZED, "File format '" + itos(FORMAT_VERSION) + "." + itos(ver_major) + "." + itos(ver_minor) + "' is too new! Please upgrade to a new engine version: " + local_path + ".");
 	}
 
 	// Since we're not actually converting the file contents, leave the version
@@ -1477,7 +1467,7 @@ void ResourceFormatSaverBinaryInstance::write_variant(FileAccess *f, const Varia
 		case Variant::_RID: {
 
 			f->store_32(VARIANT_RID);
-			WARN_PRINT("Can't save RIDs");
+			WARN_PRINT("Can't save RIDs.");
 			RID val = p_property;
 			f->store_32(val.get_id());
 		} break;
@@ -1497,8 +1487,7 @@ void ResourceFormatSaverBinaryInstance::write_variant(FileAccess *f, const Varia
 
 				if (!resource_set.has(res)) {
 					f->store_32(OBJECT_EMPTY);
-					ERR_EXPLAIN("Resource was not pre cached for the resource section, most likely due to circular refedence.");
-					ERR_FAIL();
+					ERR_FAIL_MSG("Resource was not pre cached for the resource section, most likely due to circular reference.");
 				}
 
 				f->store_32(OBJECT_INTERNAL_RESOURCE);
@@ -1629,8 +1618,7 @@ void ResourceFormatSaverBinaryInstance::write_variant(FileAccess *f, const Varia
 		} break;
 		default: {
 
-			ERR_EXPLAIN("Invalid variant");
-			ERR_FAIL();
+			ERR_FAIL_MSG("Invalid variant.");
 		}
 	}
 }
diff --git a/core/io/resource_loader.cpp b/core/io/resource_loader.cpp
index 35af58ad07..9e954890bc 100644
--- a/core/io/resource_loader.cpp
+++ b/core/io/resource_loader.cpp
@@ -275,12 +275,9 @@ RES ResourceLoader::_load(const String &p_path, const String &p_original_path, c
 		return res;
 	}
 
-	if (found) {
-		ERR_EXPLAIN("Failed loading resource: " + p_path);
-	} else {
-		ERR_EXPLAIN("No loader found for resource: " + p_path);
-	}
-	ERR_FAIL_V(RES());
+	ERR_FAIL_COND_V_MSG(found, RES(), "Failed loading resource: " + p_path + ".");
+
+	ERR_FAIL_V_MSG(RES(), "No loader found for resource: " + p_path + ".");
 }
 
 bool ResourceLoader::_add_to_loading_map(const String &p_path) {
@@ -355,10 +352,7 @@ RES ResourceLoader::load(const String &p_path, const String &p_type_hint, bool p
 
 		{
 			bool success = _add_to_loading_map(local_path);
-			if (!success) {
-				ERR_EXPLAIN("Resource: '" + local_path + "' is already being loaded. Cyclic reference?");
-				ERR_FAIL_V(RES());
-			}
+			ERR_FAIL_COND_V_MSG(!success, RES(), "Resource: '" + local_path + "' is already being loaded. Cyclic reference?");
 		}
 
 		//lock first if possible
@@ -395,8 +389,7 @@ RES ResourceLoader::load(const String &p_path, const String &p_type_hint, bool p
 		if (!p_no_cache) {
 			_remove_from_loading_map(local_path);
 		}
-		ERR_EXPLAIN("Remapping '" + local_path + "'failed.");
-		ERR_FAIL_V(RES());
+		ERR_FAIL_V_MSG(RES(), "Remapping '" + local_path + "' failed.");
 	}
 
 	print_verbose("Loading resource: " + path);
@@ -479,10 +472,7 @@ Ref<ResourceInteractiveLoader> ResourceLoader::load_interactive(const String &p_
 	if (!p_no_cache) {
 
 		bool success = _add_to_loading_map(local_path);
-		if (!success) {
-			ERR_EXPLAIN("Resource: '" + local_path + "' is already being loaded. Cyclic reference?");
-			ERR_FAIL_V(RES());
-		}
+		ERR_FAIL_COND_V_MSG(!success, RES(), "Resource: '" + local_path + "' is already being loaded. Cyclic reference?");
 
 		if (ResourceCache::has(local_path)) {
 
@@ -503,8 +493,7 @@ Ref<ResourceInteractiveLoader> ResourceLoader::load_interactive(const String &p_
 		if (!p_no_cache) {
 			_remove_from_loading_map(local_path);
 		}
-		ERR_EXPLAIN("Remapping '" + local_path + "'failed.");
-		ERR_FAIL_V(RES());
+		ERR_FAIL_V_MSG(RES(), "Remapping '" + local_path + "' failed.");
 	}
 
 	print_verbose("Loading resource: " + path);
@@ -534,12 +523,9 @@ Ref<ResourceInteractiveLoader> ResourceLoader::load_interactive(const String &p_
 		_remove_from_loading_map(local_path);
 	}
 
-	if (found) {
-		ERR_EXPLAIN("Failed loading resource: " + path);
-	} else {
-		ERR_EXPLAIN("No loader found for resource: " + path);
-	}
-	ERR_FAIL_V(Ref<ResourceInteractiveLoader>());
+	ERR_FAIL_COND_V_MSG(found, Ref<ResourceInteractiveLoader>(), "Failed loading resource: " + path + ".");
+
+	ERR_FAIL_V_MSG(Ref<ResourceInteractiveLoader>(), "No loader found for resource: " + path + ".");
 }
 
 void ResourceLoader::add_resource_format_loader(Ref<ResourceFormatLoader> p_format_loader, bool p_at_front) {
@@ -801,7 +787,7 @@ String ResourceLoader::_path_remap(const String &p_path, bool *r_translation_rem
 				if (err == ERR_FILE_EOF) {
 					break;
 				} else if (err != OK) {
-					ERR_PRINTS("Parse error: " + p_path + ".remap:" + itos(lines) + " error: " + error_text);
+					ERR_PRINTS("Parse error: " + p_path + ".remap:" + itos(lines) + " error: " + error_text + ".");
 					break;
 				}
 
@@ -932,13 +918,11 @@ bool ResourceLoader::add_custom_resource_format_loader(String script_path) {
 	Ref<Script> s = res;
 	StringName ibt = s->get_instance_base_type();
 	bool valid_type = ClassDB::is_parent_class(ibt, "ResourceFormatLoader");
-	ERR_EXPLAIN("Script does not inherit a CustomResourceLoader: " + script_path);
-	ERR_FAIL_COND_V(!valid_type, false);
+	ERR_FAIL_COND_V_MSG(!valid_type, false, "Script does not inherit a CustomResourceLoader: " + script_path + ".");
 
 	Object *obj = ClassDB::instance(ibt);
 
-	ERR_EXPLAIN("Cannot instance script as custom resource loader, expected 'ResourceFormatLoader' inheritance, got: " + String(ibt));
-	ERR_FAIL_COND_V(obj == NULL, false);
+	ERR_FAIL_COND_V_MSG(obj == NULL, false, "Cannot instance script as custom resource loader, expected 'ResourceFormatLoader' inheritance, got: " + String(ibt) + ".");
 
 	ResourceFormatLoader *crl = Object::cast_to<ResourceFormatLoader>(obj);
 	crl->set_script(s.get_ref_ptr());
diff --git a/core/io/resource_saver.cpp b/core/io/resource_saver.cpp
index 369cd93442..a9ad62afe6 100644
--- a/core/io/resource_saver.cpp
+++ b/core/io/resource_saver.cpp
@@ -214,13 +214,11 @@ bool ResourceSaver::add_custom_resource_format_saver(String script_path) {
 	Ref<Script> s = res;
 	StringName ibt = s->get_instance_base_type();
 	bool valid_type = ClassDB::is_parent_class(ibt, "ResourceFormatSaver");
-	ERR_EXPLAIN("Script does not inherit a CustomResourceSaver: " + script_path);
-	ERR_FAIL_COND_V(!valid_type, false);
+	ERR_FAIL_COND_V_MSG(!valid_type, false, "Script does not inherit a CustomResourceSaver: " + script_path + ".");
 
 	Object *obj = ClassDB::instance(ibt);
 
-	ERR_EXPLAIN("Cannot instance script as custom resource saver, expected 'ResourceFormatSaver' inheritance, got: " + String(ibt));
-	ERR_FAIL_COND_V(obj == NULL, false);
+	ERR_FAIL_COND_V_MSG(obj == NULL, false, "Cannot instance script as custom resource saver, expected 'ResourceFormatSaver' inheritance, got: " + String(ibt) + ".");
 
 	ResourceFormatSaver *crl = Object::cast_to<ResourceFormatSaver>(obj);
 	crl->set_script(s.get_ref_ptr());
diff --git a/core/io/translation_loader_po.cpp b/core/io/translation_loader_po.cpp
index 67a0a905bd..e8e71c10ca 100644
--- a/core/io/translation_loader_po.cpp
+++ b/core/io/translation_loader_po.cpp
@@ -67,8 +67,7 @@ RES TranslationLoaderPO::load_translation(FileAccess *f, Error *r_error, const S
 
 			if (status == STATUS_READING_ID) {
 				memdelete(f);
-				ERR_EXPLAIN(p_path + ":" + itos(line) + " Unexpected EOF while reading 'msgid' at file: ");
-				ERR_FAIL_V(RES());
+				ERR_FAIL_V_MSG(RES(), p_path + ":" + itos(line) + " Unexpected EOF while reading 'msgid' at file: ");
 			} else {
 				break;
 			}
@@ -79,8 +78,7 @@ RES TranslationLoaderPO::load_translation(FileAccess *f, Error *r_error, const S
 			if (status == STATUS_READING_ID) {
 
 				memdelete(f);
-				ERR_EXPLAIN(p_path + ":" + itos(line) + " Unexpected 'msgid', was expecting 'msgstr' while parsing: ");
-				ERR_FAIL_V(RES());
+				ERR_FAIL_V_MSG(RES(), p_path + ":" + itos(line) + " Unexpected 'msgid', was expecting 'msgstr' while parsing: ");
 			}
 
 			if (msg_id != "") {
@@ -102,8 +100,7 @@ RES TranslationLoaderPO::load_translation(FileAccess *f, Error *r_error, const S
 			if (status != STATUS_READING_ID) {
 
 				memdelete(f);
-				ERR_EXPLAIN(p_path + ":" + itos(line) + " Unexpected 'msgstr', was expecting 'msgid' while parsing: ");
-				ERR_FAIL_V(RES());
+				ERR_FAIL_V_MSG(RES(), p_path + ":" + itos(line) + " Unexpected 'msgstr', was expecting 'msgid' while parsing: ");
 			}
 
 			l = l.substr(6, l.length()).strip_edges();
@@ -118,11 +115,7 @@ RES TranslationLoaderPO::load_translation(FileAccess *f, Error *r_error, const S
 			continue; //nothing to read or comment
 		}
 
-		if (!l.begins_with("\"") || status == STATUS_NONE) {
-			//not a string? failure!
-			ERR_EXPLAIN(p_path + ":" + itos(line) + " Invalid line '" + l + "' while parsing: ");
-			ERR_FAIL_V(RES());
-		}
+		ERR_FAIL_COND_V_MSG(!l.begins_with("\"") || status == STATUS_NONE, RES(), p_path + ":" + itos(line) + " Invalid line '" + l + "' while parsing: ");
 
 		l = l.substr(1, l.length());
 		//find final quote
@@ -135,10 +128,7 @@ RES TranslationLoaderPO::load_translation(FileAccess *f, Error *r_error, const S
 			}
 		}
 
-		if (end_pos == -1) {
-			ERR_EXPLAIN(p_path + ":" + itos(line) + " Expected '\"' at end of message while parsing file: ");
-			ERR_FAIL_V(RES());
-		}
+		ERR_FAIL_COND_V_MSG(end_pos == -1, RES(), p_path + ":" + itos(line) + " Expected '\"' at end of message while parsing file: ");
 
 		l = l.substr(0, end_pos);
 		l = l.c_unescape();
@@ -163,10 +153,7 @@ RES TranslationLoaderPO::load_translation(FileAccess *f, Error *r_error, const S
 			config = msg_str;
 	}
 
-	if (config == "") {
-		ERR_EXPLAIN("No config found in file: " + p_path);
-		ERR_FAIL_V(RES());
-	}
+	ERR_FAIL_COND_V_MSG(config == "", RES(), "No config found in file: " + p_path + ".");
 
 	Vector<String> configs = config.split("\n");
 	for (int i = 0; i < configs.size(); i++) {
diff --git a/core/io/xml_parser.cpp b/core/io/xml_parser.cpp
index 82527d3f38..9487947365 100644
--- a/core/io/xml_parser.cpp
+++ b/core/io/xml_parser.cpp
@@ -443,10 +443,8 @@ String XMLParser::get_attribute_value(const String &p_name) const {
 		}
 	}
 
-	if (idx < 0) {
-		ERR_EXPLAIN("Attribute not found: " + p_name);
-	}
-	ERR_FAIL_COND_V(idx < 0, "");
+	ERR_FAIL_COND_V_MSG(idx < 0, "", "Attribute not found: " + p_name + ".");
+
 	return attributes[idx].value;
 }