User comment from crash group:
  491       void FStaticMeshVertexBuffer::BindLightMapVertexBuffer(const FVertexFactory* VertexFactory, FStaticMeshDataType& Data, int LightMapCoordinateIndex) const
  492       {
  493       	check(LightMapCoordinateIndex < (int)GetNumTexCoords() && LightMapCoordinateIndex >= 0);
  494 ***** 	Data.LightMapCoordinateIndex = LightMapCoordinateIndex;
  495       	Data.NumTexCoords = GetNumTexCoords();
  496       
  497       	{
  498       		Data.TextureCoordinatesSRV = TextureCoordinatesSRV;
  499       	}
  500       	
  501       	{
  502       		EVertexElementType UVVertexElementType = VET_None;
  503       		uint32 UVSizeInBytes = 0;
  504       
  505       		if (GetUseFullPrecisionUVs())
  506       		{
  507       			UVSizeInBytes = sizeof(TStaticMeshVertexUVsTypeSelector<EStaticMeshVertexUVType::HighPrecision>::UVsTypeT);
  508       			UVVertexElementType = VET_Float2;
  509       		}
1. Open empty scene
2. Place Spline Mesh Actor
3. Import attached static mesh test_box.obj
4. Select it inside Spline Mesh Actor (Static Mesh field)
5. Reimport test_box.obj
Assertion failed: LightMapCoordinateIndex < (int)GetNumTexCoords() && LightMapCoordinateIndex >= 0 [File:D:\Build\++UE4+Release-4.19+Compile\Sync\Engine\Source\Runtime\Engine\Private\Rendering\StaticMeshVertexBuffer.cpp] [Line: 494] UE4Editor_Engine!FStaticMeshVertexBuffer::BindLightMapVertexBuffer() [staticmeshvertexbuffer.cpp:495] UE4Editor_Engine!<lambda_66eb8eb67e8b3cb6eadf4ee824e3bf1e>::operator() [splinemeshcomponent.cpp:159] UE4Editor_Engine!TGraphTask<TEnqueueUniqueRenderCommandType<`FSplineMeshSceneProxy::InitVertexFactory'::`2'::InitSplineMeshVertexFactoryName,<lambda_66eb8eb67e8b3cb6eadf4ee824e3bf1e> > >::ExecuteTask() [taskgraphinterfaces.h:829] UE4Editor_Core!FNamedTaskThread::ProcessTasksNamedThread() [taskgraph.cpp:665] UE4Editor_Core!FNamedTaskThread::ProcessTasksUntilQuit() [taskgraph.cpp:574] UE4Editor_RenderCore!RenderingThreadMain() [renderingthread.cpp:331] UE4Editor_RenderCore!FRenderingThread::Run() [renderingthread.cpp:465] UE4Editor_Core!FRunnableThreadWin::Run() [windowsrunnablethread.cpp:76]
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-56321 in the post.
| 0 | 
| Component | UE - Graphics Features | 
|---|---|
| Affects Versions | 4.19 | 
| Target Fix | 4.19.1 | 
| Fix Commit | 3964893 | 
|---|
| Created | Mar 20, 2018 | 
|---|---|
| Resolved | Mar 26, 2018 | 
| Updated | May 1, 2018 |