diff --git a/FrontEnd/EVIL.evil/EvmFrontEnd.cs b/FrontEnd/EVIL.evil/EvmFrontEnd.cs
index e06869f3..47bc9c2a 100644
--- a/FrontEnd/EVIL.evil/EvmFrontEnd.cs
+++ b/FrontEnd/EVIL.evil/EvmFrontEnd.cs
@@ -275,13 +275,25 @@ private void SetIncludePathsGlobal()
 
         private void CrashHandler(Fiber fiber, Exception exception)
         {
-            var callStack = fiber.CallStack;
-            var top = callStack.Peek().As<ScriptStackFrame>();
             var fiberArray = _vm.Scheduler.Fibers.ToArray();
             var fiberIndex = Array.IndexOf(fiberArray, fiber);
+            
+            var callStack = fiber.CallStack;
+            var top = callStack.Peek();
+            ScriptStackFrame? scriptTop = null;
 
             var sb = new StringBuilder();
-            sb.AppendLine($"Runtime error in fiber {fiberIndex}, function {top.Chunk.Name} (def. in {top.Chunk.DebugDatabase.DefinedInFile}:{top.Chunk.DebugDatabase.DefinedOnLine}): {exception.Message}");
+            
+            if (top is NativeStackFrame)
+            {
+                scriptTop = callStack[1].As<ScriptStackFrame>();
+            }
+            else
+            {
+                scriptTop = top.As<ScriptStackFrame>();
+            }
+
+            sb.AppendLine($"Runtime error in fiber {fiberIndex}, function {scriptTop.Chunk.Name} (def. in {scriptTop.Chunk.DebugDatabase.DefinedInFile}:{scriptTop.Chunk.DebugDatabase.DefinedOnLine}): {exception.Message}");
             sb.AppendLine();
             sb.AppendLine("Stack trace:");
             sb.Append(fiber.StackTrace(false));
diff --git a/VirtualMachine/Ceres.Runtime/Extensions/FunctionArguments.Expect.cs b/VirtualMachine/Ceres.Runtime/Extensions/FunctionArguments.Expect.cs
index e6f3aeb6..ee1ab53b 100644
--- a/VirtualMachine/Ceres.Runtime/Extensions/FunctionArguments.Expect.cs
+++ b/VirtualMachine/Ceres.Runtime/Extensions/FunctionArguments.Expect.cs
@@ -17,9 +17,9 @@ public static DynamicValue[] ExpectTypeAt(this DynamicValue[] args, int index, D
 
             if (argType != type)
             {
-                if (argType == DynamicValueType.Nil)
+                if (allowNil)
                 {
-                    if (allowNil)
+                    if (argType == DynamicValueType.Nil)
                     {
                         return args;
                     }