diff --git a/IDE/mintest/src/base.cs b/IDE/mintest/src/base.cs
new file mode 100644
index 00000000..4c3ff65a
--- /dev/null
+++ b/IDE/mintest/src/base.cs
@@ -0,0 +1,87 @@
+/*using System;
+using System.Runtime.InteropServices;
+
+namespace Allegro
+{
+    public partial class AllegroAPI
+    {
+        //internal const string AllegroDllName = "allegro_monolith-5.2.dll";
+
+        public static string AllegroDllVersionName(string name)
+        {
+            var p = (int)Environment.OSVersion.Platform;
+            if ((p == 4) || (p == 6) || (p == 128))
+                return name; // Linux
+
+            // Windows
+            return name + '-' + ALLEGRO_VERSION + '.' + ALLEGRO_SUB_VERSION + ".dll";
+        }
+
+        //private const string AllegroDllName = "allegro";
+        internal const string AllegroDllName = "allegro_monolith-5.2.dll";
+
+
+        [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
+        public delegate int AppMainDelegate(int argc, string[] argv);
+
+
+        
+
+        public const int ALLEGRO_VERSION = 5;
+        public const int ALLEGRO_SUB_VERSION = 2;
+        public const int ALLEGRO_WIP_VERSION = 2;
+
+
+        /// <summary>
+        /// Not sure we need it, but since ALLEGRO_VERSION_STR contains it:
+        /// 0 = GIT
+        /// 1 = first release
+        /// 2... = hotfixes?
+        /// 
+        /// Note x.y.z (= x.y.z.0) has release number 1, and x.y.z.1 has release
+        /// number 2, just to confuse you.
+        /// </summary>
+        public const int ALLEGRO_RELEASE_NUMBER = 0;
+
+        public const string ALLEGRO_VERSION_STR = "5.2.2 (GIT)";
+        public const string ALLEGRO_DATE_STR = "2016";
+        public const int ALLEGRO_DATE = 20160731;    /* yyyymmdd */
+        public const int ALLEGRO_VERSION_INT =
+            ((ALLEGRO_VERSION << 24) | (ALLEGRO_SUB_VERSION << 16) |
+            (ALLEGRO_WIP_VERSION << 8) | ALLEGRO_RELEASE_NUMBER);
+
+        //[DllImport(AllegroDllName, CallingConvention = CallingConvention.Cdecl)]
+		//[Import(AllegroDllName)]Cdecl)]
+        public static extern UInt32 al_get_allegro_version();
+
+        [DllImport(AllegroDllName, CallingConvention = CallingConvention.Cdecl)]
+        public static extern int al_run_main(int argc,
+            [MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 0, ArraySubType = UnmanagedType.LPStr)]
+            string[] argv, AppMainDelegate main);
+
+        /*******************************************/
+        /************ Some global stuff ************/
+        /*******************************************/
+
+        /// <summary>
+        /// ALLEGRO_PI
+        /// </summary>
+        public const double ALLEGRO_PI = 3.14159265358979323846;
+
+        public static int AL_ID(byte a, byte b, byte c, byte d)
+        {
+            return (a << 24) | (b << 16) | (c << 8) | d;
+        }
+
+
+        
+        public static bool IsLinux
+        {
+            get
+            {
+                int p = (int) Environment.OSVersion.Platform;
+                return (p == 4) || (p == 6) || (p == 128);
+            }
+        }
+    }
+}*/
diff --git a/IDE/src/ui/ProjectPanel.bf b/IDE/src/ui/ProjectPanel.bf
index fcd2ab25..8561d379 100644
--- a/IDE/src/ui/ProjectPanel.bf
+++ b/IDE/src/ui/ProjectPanel.bf
@@ -1064,6 +1064,16 @@ namespace IDE.ui
 			return projectItem;
 		}
 
+		ProjectFolder GetSelectedProjectFolder()
+		{
+			let projectItem = GetSelectedProjectItem();
+			if (projectItem == null)
+				return null;
+			if (let projectFolder = projectItem as ProjectFolder)
+				return projectFolder;
+			return projectItem.mParentFolder;
+		}
+
         public void SelectItem(ListViewItem item, bool checkKeyStates = false)
         {
             if (item.Focused)
@@ -2145,7 +2155,7 @@ namespace IDE.ui
 				item = menu.AddItem("New Folder");
 				item.mOnMenuItemSelected.Add(new (item) =>
 				    {
-						var projectFolder = GetSelectedProjectItem() as ProjectFolder;
+						var projectFolder = GetSelectedProjectFolder();
 						if (projectFolder != null)
 				        {
 							if (CheckProjectModify(projectFolder.mProject))
@@ -2156,7 +2166,7 @@ namespace IDE.ui
 				item = menu.AddItem("New Class...");
 				item.mOnMenuItemSelected.Add(new (item) =>
 				    {
-						var projectFolder = GetSelectedProjectItem() as ProjectFolder;
+						var projectFolder = GetSelectedProjectFolder();
 						if (projectFolder != null)
 				        {
 							if (CheckProjectModify(projectFolder.mProject))
diff --git a/IDEHelper/Compiler/BfDefBuilder.cpp b/IDEHelper/Compiler/BfDefBuilder.cpp
index 67c26803..654a56b8 100644
--- a/IDEHelper/Compiler/BfDefBuilder.cpp
+++ b/IDEHelper/Compiler/BfDefBuilder.cpp
@@ -1467,7 +1467,12 @@ void BfDefBuilder::Visit(BfTypeDeclaration* typeDeclaration)
 				{
 					if (checkTypeDef->mDefState == BfTypeDef::DefState_AwaitingNewVersion)
 					{
-						if (isExtension == (checkTypeDef->mTypeCode == BfTypeCode_Extension))
+						// We don't allow "new revision" semantics if the 'isExtension' state changes, or
+						//  if the outer type did not use "new revision" semantics (for isExtension change on itself or other outer type)
+						bool isCompatible = (isExtension == (checkTypeDef->mTypeCode == BfTypeCode_Extension)) &&
+							(checkTypeDef->mOuterType == actualOuterTypeDef);
+						
+						if (isCompatible)
 						{
 							if (prevRevisionTypeDef == NULL)
 							{
diff --git a/IDEHelper/Compiler/BfMangler.cpp b/IDEHelper/Compiler/BfMangler.cpp
index 071bd59a..984b2141 100644
--- a/IDEHelper/Compiler/BfMangler.cpp
+++ b/IDEHelper/Compiler/BfMangler.cpp
@@ -259,7 +259,10 @@ void BfGNUMangler::FindOrCreateNameSub(MangleContext& mangleContext, StringImpl&
 		if (useModule == NULL)
 			useModule = mangleContext.mModule;
 		auto outerType = useModule->GetOuterType(typeInst);
-		FindOrCreateNameSub(mangleContext, name, outerType, curMatchIdx, matchFailed);
+		if (outerType != NULL)
+			FindOrCreateNameSub(mangleContext, name, outerType, curMatchIdx, matchFailed);
+		else
+			useModule->Fail("Failed to mangle name in BfGNUMangler::FindOrCreateNameSub");
 	}
 
 	FindOrCreateNameSub(mangleContext, name, NameSubstitute(NameSubstitute::Kind_TypeInstName, typeInst), curMatchIdx, matchFailed);
@@ -1283,7 +1286,10 @@ void BfMSMangler::Mangle(MangleContext& mangleContext, StringImpl& name, BfTypeI
 		else
 		{
 			auto outerType = useModule->GetOuterType(typeInstance);
-			Mangle(mangleContext, name, outerType, true, true);
+			if (outerType != NULL)
+				Mangle(mangleContext, name, outerType, true, true);
+			else	
+				useModule->Fail("Failed to mangle name in BfMSMangler::Mangle");
 		}
 	}
 
diff --git a/IDEHelper/Compiler/BfModuleTypeUtils.cpp b/IDEHelper/Compiler/BfModuleTypeUtils.cpp
index c6559ea4..c11ad752 100644
--- a/IDEHelper/Compiler/BfModuleTypeUtils.cpp
+++ b/IDEHelper/Compiler/BfModuleTypeUtils.cpp
@@ -4902,6 +4902,9 @@ BfType* BfModule::ResolveTypeDef(BfTypeDef* typeDef, BfPopulateType populateType
 	//BF_ASSERT(typeDef->mTypeCode != BfTypeCode_Extension);
 	BF_ASSERT(!typeDef->mIsPartial || typeDef->mIsCombinedPartial);
 
+	BF_ASSERT(typeDef->mDefState != BfTypeDef::DefState_Deleted);
+	BF_ASSERT((typeDef->mOuterType == NULL) || (typeDef->mOuterType->mDefState != BfTypeDef::DefState_Deleted));
+
 	if (typeDef->mGenericParamDefs.size() != 0)
 		return ResolveTypeDef(typeDef, BfTypeVector(), populateType);