Using extension methods crashes the editor

[errmalt]

Example of an extension method that crashes the editor:

namespace Game
{
    static class ExampleExtensions
    {
        public static int test(this Enum enum1)
        {
            return 1;
        }
    }
}

Log output:

Fatal error: [File:E:\unrealcs_v4.14.3_v1.0\HostProject\Plugins\UnrealCS\Source\MonoPlugin\Private\MonoDomain.cpp] [Line: 211] 
* Assertion: should not be reached at ..\mono\metadata\loader.c:299



KERNELBASE
UE4Editor_Core
UE4Editor_Core
UE4Editor_Core
UE4Editor_MonoPlugin!MonoLog() [e:\unrealcs_v4.14.3_v1.0\hostproject\plugins\unrealcs\source\monoplugin\private\monodomain.cpp:211]
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
monosgen_2_0
UE4Editor_MonoPlugin!FMonoDomain::NativeHotReload() [e:\unrealcs_v4.14.3_v1.0\hostproject\plugins\unrealcs\source\monoplugin\private\monodomain.cpp:611]
UE4Editor_MonoPlugin!FMonoDomain::HotReload() [e:\unrealcs_v4.14.3_v1.0\hostproject\plugins\unrealcs\source\monoplugin\private\monodomain.cpp:690]
UE4Editor_MonoPlugin!FMonoDomain::Tick() [e:\unrealcs_v4.14.3_v1.0\hostproject\plugins\unrealcs\source\monoplugin\private\monodomain.cpp:750]
UE4Editor_Engine
UE4Editor_UnrealEd
UE4Editor_UnrealEd
UE4Editor
UE4Editor
UE4Editor
UE4Editor
UE4Editor
kernel32
ntdll

[xiongfang]

Is this file AssemblyExportedClass.cs in your C# project folder?
It should be in your game project directory Project/Game/AssemblyExportedClass.cs.

[errmalt]

Yes it is. This happens in a new barebones project as soon as I add a file that contains just this extension method and when I build the project the Unreal Editor crashes. Tell me if you have any issues reproducing this, I can reproduce it 100% of the time.