Simplygon in custom built engine 4.13

Our team use a custom built unreal4.13. And we are trying to add simplygon to our engine.

The simplygon plugins worked on official unreal4.13(download in launcher). But failed on our custom engine.

I know that 4.14 has built-in auto mesh reduction. But it is not easy for us to update engine version.

What should I do to make it work on 4.13? Or How can I copy the auto mesh reduction from 4.14 to 4.13?

found solution

change “CheckModuleCompatibility” function in Source/Runtime/Core/Private\Modules\ModuleManager.cpp

bool FModuleManager::CheckModuleCompatibility(const TCHAR* Filename)
{
	int32 ModuleApiVersion = FPlatformProcess::GetDllApiVersion(Filename);
	int32 CompiledInApiVersion = MODULE_API_VERSION;
	return true;
	if (ModuleApiVersion != CompiledInApiVersion)
	{
		if (wcscmp(Filename, TEXT("UE4Editor-SimplygonMeshReduction.dll")) == 0
			|| wcscmp(Filename, TEXT("UE4Editor-SimplygonSwarm.dll")) == 0)
		{
			return true;
		}
		UE_LOG(LogModuleManager, Warning, TEXT("Found module file %s (API version %d), but it was incompatible with the current engine API version (%d). This is likely a stale module that must be recompiled."), Filename, ModuleApiVersion, CompiledInApiVersion);
		return false;
	}

	return true;
}