Index: ps/trunk/binaries/data/mods/public/gui/gamesetup/gamesetup.js
===================================================================
--- ps/trunk/binaries/data/mods/public/gui/gamesetup/gamesetup.js
+++ ps/trunk/binaries/data/mods/public/gui/gamesetup/gamesetup.js
@@ -1713,7 +1713,7 @@
 		let file = g_GameAttributes.mapPath + mapFile;
 		let mapData = loadMapData(file);
 
-		if (!mapData.settings || filterFunc && !filterFunc(mapData.settings.Keywords || []))
+		if (!mapData || !mapData.settings || filterFunc && !filterFunc(mapData.settings.Keywords || []))
 			continue;
 
 		maps.push({
Index: ps/trunk/source/graphics/MapGenerator.cpp
===================================================================
--- ps/trunk/source/graphics/MapGenerator.cpp
+++ ps/trunk/source/graphics/MapGenerator.cpp
@@ -334,14 +334,28 @@
 // See CMapReader::UnpackTerrain, CMapReader::ParseTerrain for the reordering
 JS::Value CMapGeneratorWorker::LoadMapTerrain(ScriptInterface::CxPrivate* pCxPrivate, const VfsPath& filename)
 {
+	CMapGeneratorWorker* self = static_cast<CMapGeneratorWorker*>(pCxPrivate->pCBData);
+	JSContext* cx = self->m_ScriptInterface->GetContext();
+	JSAutoRequest rq(cx);
+
 	if (!VfsFileExists(filename))
-		throw PSERROR_File_OpenFailed();
+	{
+		self->m_ScriptInterface->ReportError(
+			("Terrain file \"" +  filename.string8() +  "\" does not exist!").c_str());
+
+		return JS::UndefinedValue();
+	}
 
 	CFileUnpacker unpacker;
 	unpacker.Read(filename, "PSMP");
 
 	if (unpacker.GetVersion() < CMapIO::FILE_READ_VERSION)
-		throw PSERROR_File_InvalidVersion();
+	{
+		self->m_ScriptInterface->ReportError(
+			("Could not load terrain file \"" +  filename.string8() +  "\" too old version!").c_str());
+
+		return JS::UndefinedValue();
+	}
 
 	// unpack size
 	ssize_t patchesPerSide = (ssize_t)unpacker.UnpackSize();
@@ -384,9 +398,6 @@
 		}
 	}
 
-	CMapGeneratorWorker* self = static_cast<CMapGeneratorWorker*>(pCxPrivate->pCBData);
-	JSContext* cx = self->m_ScriptInterface->GetContext();
-	JSAutoRequest rq(cx);
 	JS::RootedValue returnValue(cx, JS::ObjectValue(*JS_NewPlainObject(cx)));
 	self->m_ScriptInterface->SetProperty(returnValue, "height", heightmap);
 	self->m_ScriptInterface->SetProperty(returnValue, "textureNames", textureNames);
Index: ps/trunk/source/graphics/MapReader.cpp
===================================================================
--- ps/trunk/source/graphics/MapReader.cpp
+++ ps/trunk/source/graphics/MapReader.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2017 Wildfire Games.
+/* Copyright (C) 2019 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -102,7 +102,7 @@
 
 	// check oldest supported version
 	if (file_format_version < FILE_READ_VERSION)
-		throw PSERROR_File_InvalidVersion();
+		throw PSERROR_Game_World_MapLoadFailed("Could not load terrain file - too old version!");
 
 	// delete all existing entities
 	if (pSimulation2)
@@ -451,7 +451,7 @@
 	node_idx = entity_idx = 0;
 
 	if (xmb_file.Load(g_VFS, xml_filename, "scenario") != PSRETURN_OK)
-		throw PSERROR_File_ReadFailed();
+		throw PSERROR_Game_World_MapLoadFailed("Could not read map XML file!");
 
 	// define the elements and attributes that are frequently used in the XML file,
 	// so we don't need to do lots of string construction and comparison when