With ray tracing turned on, clicking on the isolate material option next to a material slot on a skeletal mesh with more than one material slot, causes the editor to crash.
Found in 4.22 CL# 7053647, 4.23 CL# 7208101, 4.24 CL# 7210422
Results:
Crash
Expected:
Material element would be isolated correctly
Assertion failed: Instance.Materials.Num() == Instance.Geometry->Initializer.Segments.Num() || (Instance.Geometry->Initializer.Segments.Num() == 0 && Instance.Materials.Num() == 1) [File:D:/JeremyMain/Engine/Source/Runtime/Renderer/Private/DeferredShadingRenderer.cpp] [Line: 731] UE4Editor_Core!FWindowsErrorOutputDevice::Serialize() [d:\jeremymain\engine\source\runtime\core\private\windows\windowserroroutputdevice.cpp:79] UE4Editor_Core!FOutputDevice::LogfImpl() [d:\jeremymain\engine\source\runtime\core\private\misc\outputdevice.cpp:71] UE4Editor_Core!AssertFailedImplV() [d:\jeremymain\engine\source\runtime\core\private\misc\assertionmacros.cpp:101] UE4Editor_Core!FDebug::CheckVerifyFailedImpl() [d:\jeremymain\engine\source\runtime\core\private\misc\assertionmacros.cpp:445] UE4Editor_Renderer!FDeferredShadingSceneRenderer::GatherRayTracingWorldInstances() [d:\jeremymain\engine\source\runtime\renderer\private\deferredshadingrenderer.cpp:731] UE4Editor_Renderer!FDeferredShadingSceneRenderer::Render() [d:\jeremymain\engine\source\runtime\renderer\private\deferredshadingrenderer.cpp:838] UE4Editor_Renderer!RenderViewFamily_RenderThread() [d:\jeremymain\engine\source\runtime\renderer\private\scenerendering.cpp:3242] UE4Editor_Renderer!TGraphTask<TEnqueueUniqueRenderCommandType<`FRendererModule::BeginRenderingViewFamily'::`27'::FDrawSceneCommandName,<lambda_98974a148448e2faeb6b39d7ee44228d> > >::ExecuteTask() [d:\jeremymain\engine\source\runtime\core\public\async\taskgraphinterfaces.h:847] UE4Editor_Core!FNamedTaskThread::ProcessTasksNamedThread() [d:\jeremymain\engine\source\runtime\core\private\async\taskgraph.cpp:686] UE4Editor_Core!FNamedTaskThread::ProcessTasksUntilQuit() [d:\jeremymain\engine\source\runtime\core\private\async\taskgraph.cpp:583] UE4Editor_RenderCore!RenderingThreadMain() [d:\jeremymain\engine\source\runtime\rendercore\private\renderingthread.cpp:340] UE4Editor_RenderCore!FRenderingThread::Run() [d:\jeremymain\engine\source\runtime\rendercore\private\renderingthread.cpp:471] UE4Editor_Core!FRunnableThreadWin::Run() [d:\jeremymain\engine\source\runtime\core\private\windows\windowsrunnablethread.cpp:96]
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-76848 in the post.