This is a somewhat common crash that has occurred since at least the 4.16 release.
User Descriptions
Source Context
70 void FSkeletalMeshObject::UpdateMinDesiredLODLevel(const FSceneView* View, const FBoxSphereBounds& Bounds, int32 FrameNumber) 71 { 72 static const auto* SkeletalMeshLODRadiusScale = IConsoleManager::Get().FindTConsoleVariableDataFloat(TEXT("r.SkeletalMeshLODRadiusScale")); 73 float LODScale = FMath::Clamp(SkeletalMeshLODRadiusScale->GetValueOnRenderThread(), 0.25f, 1.0f); 74 75 const float ScreenRadiusSquared = ComputeBoundsScreenRadiusSquared(Bounds.Origin, Bounds.SphereRadius, *View) * LODScale * LODScale; 76 77 checkf( SkeletalMeshLODInfo.Num() == SkeletalMeshResource->LODModels.Num(), TEXT("Mismatched LOD arrays. SkeletalMeshLODInfo.Num() = %d, SkeletalMeshResource->LODModels.Num() = %d"), SkeletalMeshLODInfo.Num(), SkeletalMeshResource->LODModels.Num()); 78 79 // Need the current LOD 80 ***** const int32 CurrentLODLevel = GetLOD(); 81 const float HysteresisOffset = 0.f; 82 83 int32 NewLODLevel = 0;
repro steps currently unknown, but based on user descriptions seems related to reimporting
Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\Build\++UE4+Release-4.17+Compile\Sync\Engine\Source\Runtime\Core\Public\Containers/Array.h] [Line: 596] Array index out of bounds: -572662308 from an array of size -572662307 UE4Editor_Engine!FSkeletalMeshObject::UpdateMinDesiredLODLevel() [skeletalrender.cpp:81] UE4Editor_Engine!FSkeletalMeshSceneProxy::GetMeshElementsConditionallySelectable() [skeletalmesh.cpp:5318] UE4Editor_UnrealEd!FDebugSkelMeshSceneProxy::GetDynamicMeshElements() [debugskelmeshcomponent.cpp:958] UE4Editor_Renderer!FSceneRenderer::GatherDynamicMeshElements() [scenevisibility.cpp:1973] UE4Editor_Renderer!FSceneRenderer::ComputeViewVisibility() [scenevisibility.cpp:2634] UE4Editor_Renderer!FDeferredShadingSceneRenderer::InitViews() [scenevisibility.cpp:2880] UE4Editor_Renderer!FDeferredShadingSceneRenderer::RenderHitProxies() [scenehitproxyrendering.cpp:656] UE4Editor_Renderer!RenderViewFamily_RenderThread() [scenerendering.cpp:1842] UE4Editor_Renderer!TGraphTask<`FRendererModule::BeginRenderingViewFamily'::`26'::EURCMacro_FDrawSceneCommand>::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-51935 in the post.