diff --git a/AssemblyData/AssemblyService.cs b/AssemblyData/AssemblyService.cs
index fe4bbb4c..f9aba700 100644
--- a/AssemblyData/AssemblyService.cs
+++ b/AssemblyData/AssemblyService.cs
@@ -83,12 +83,21 @@ namespace AssemblyData {
 
 		public object[] decryptStrings(int stringDecrypterMethod, object[] args, int callerToken) {
 			checkStringDecrypter();
-			var caller = assembly.GetModules()[0].ResolveMethod(callerToken);
+			var caller = getCaller(callerToken);
 			foreach (var arg in args)
 				SimpleData.unpack((object[])arg);
 			return SimpleData.pack(stringDecrypter.decryptStrings(stringDecrypterMethod, args, caller));
 		}
 
+		MethodBase getCaller(int callerToken) {
+			try {
+				return assembly.GetModules()[0].ResolveMethod(callerToken);
+			}
+			catch {
+				return null;
+			}
+		}
+
 		public void exit() {
 			exitEvent.Set();
 		}
diff --git a/AssemblyData/methodsrewriter/MModule.cs b/AssemblyData/methodsrewriter/MModule.cs
index 24031a59..8041bba3 100644
--- a/AssemblyData/methodsrewriter/MModule.cs
+++ b/AssemblyData/methodsrewriter/MModule.cs
@@ -40,17 +40,21 @@ namespace AssemblyData.methodsrewriter {
 		}
 
 		void initTokenToType() {
-			var tmpTokenToType = new Dictionary<int, Type>();
-			var tmpTokenToTypeDefinition = new Dictionary<int, TypeDefinition>();
-			foreach (var t in module.GetTypes())
-				tmpTokenToType[t.MetadataToken] = t;
-			foreach (var t in moduleDefinition.GetTypes())
-				tmpTokenToTypeDefinition[t.MetadataToken.ToInt32()] = t;
 			moduleType = DotNetUtils.getModuleType(moduleDefinition);
-			foreach (var token in tmpTokenToType.Keys) {
-				var mtype = new MType(tmpTokenToType[token], tmpTokenToTypeDefinition[token]);
+			foreach (var typeDefinition in moduleDefinition.GetTypes()) {
+				int token = typeDefinition.MetadataToken.ToInt32();
+				Type type;
+				try {
+					type = module.ResolveType(token);
+				}
+				catch {
+					tokenToType[token] = null;
+					typeReferenceToType.add(typeDefinition, null);
+					continue;
+				}
+				var mtype = new MType(type, typeDefinition);
 				tokenToType[token] = mtype;
-				typeReferenceToType.add(mtype.typeDefinition, mtype);
+				typeReferenceToType.add(typeDefinition, mtype);
 			}
 		}
 
diff --git a/AssemblyData/methodsrewriter/MethodsRewriter.cs b/AssemblyData/methodsrewriter/MethodsRewriter.cs
index 20e9bf25..27e6c949 100644
--- a/AssemblyData/methodsrewriter/MethodsRewriter.cs
+++ b/AssemblyData/methodsrewriter/MethodsRewriter.cs
@@ -165,6 +165,8 @@ namespace AssemblyData.methodsrewriter {
 		}
 
 		public void setCaller(RewrittenMethod rewrittenMethod, MethodBase caller) {
+			if (caller == null)
+				return;
 			var newMethodInfo = getNewMethodInfo(rewrittenMethod.Method.Name);
 			newStackMethodDict[newMethodInfo] = caller;
 		}