This is a trending crash coming out of the 4.17 release that also occurred with some frequency during 4.16.
User Descriptions
Source Context
239 // If we are the default material, must not try to fall back to the default material in an error state as that will be infinite recursion 240 check(!Material->IsDefaultMaterial()); 241 242 ***** return GetFallbackRenderProxy().GetMaterial(InFeatureLevel); 243 } 244 245 virtual FMaterial* GetMaterialNoFallback(ERHIFeatureLevel::Type InFeatureLevel) const 246 { 247 checkSlow(IsInRenderingThread()); 248 return Material->GetMaterialResource(InFeatureLevel); 249 }
repro steps currently unknown
Assertion failed: !Material->IsDefaultMaterial() [File:D:\Build\++UE4+Release-4.17+Compile\Sync\Engine\Source\Runtime\Engine\Private\Materials\Material.cpp] [Line: 241] UE4Editor_Engine!FDefaultMaterialInstance::GetMaterial() [material.cpp:243] UE4Editor_Engine!FStaticMeshSceneProxy::DrawStaticElements() [staticmeshrender.cpp:742] UE4Editor_Renderer!FPrimitiveSceneInfo::AddStaticMeshes() [primitivesceneinfo.cpp:149] UE4Editor_Renderer!FPrimitiveSceneInfo::AddToScene() [primitivesceneinfo.cpp:204] UE4Editor_Renderer!FScene::AddPrimitiveSceneInfo_RenderThread() [rendererscene.cpp:517] UE4Editor_Renderer!<lambda_0628b7e343e078d62bb69bb7a0b80e2d>::operator() [rendererscene.cpp:787] UE4Editor_Renderer!TGraphTask<TEnqueueUniqueRenderCommandType<`FScene::AddPrimitive'::`2'::AddPrimitiveCommandName,<lambda_0628b7e343e078d62bb69bb7a0b80e2d> > >::ExecuteTask() [taskgraphinterfaces.h:784] UE4Editor_Core!FNamedTaskThread::ProcessTasksNamedThread() [taskgraph.cpp:650] UE4Editor_Core!FNamedTaskThread::ProcessTasksUntilQuit() [taskgraph.cpp:559] UE4Editor_RenderCore!RenderingThreadMain() [renderingthread.cpp:325] UE4Editor_RenderCore!FRenderingThread::Run() [renderingthread.cpp:459] 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-48404 in the post.