Rampant crashing when using Plane Cut/MatEd

[hexen1337]

Lately I’ve been having mesh attribute related crashes when performing plane cuts and even attempting to fix this by removing and assigning a new active material in modelling mode, still results in the same crash. It’s extremely annoying as I can’t get any work done. This only seems to be happening on mirrored meshes. Installing debugging symbols to really see what is going on, but doubt I’ll know what to do with the information.

The meshes are fairly high poly, it’s not a PC limitation 64gb ddr5, 4090, 13900kf etc. It’s definately a bug of sorts, sometimes I can delete the duplicated mesh, and then create a new duplicate and get the plane cut off. However it’s a very annoying problem. Anyone else actually making these tools do any real work, running into issues?

[hexen1337]

Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xffffffffffffffff

UnrealEditor_MeshConversion!TConstSetBitIterator::FindFirstSetBit() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\BitArray.h:1863]
UnrealEditor_MeshConversion!FAttributesSetBase::Insert() [D:\build++UE5\Sync\Engine\Source\Runtime\MeshDescription\Public\MeshAttributeArray.h:1745]
UnrealEditor_MeshConversion!FMeshElementContainer::Add() [D:\build++UE5\Sync\Engine\Source\Runtime\MeshDescription\Public\MeshElementContainer.h:82]
UnrealEditor_MeshConversion!FMeshDescription::CreateVertexInstance() [D:\build++UE5\Sync\Engine\Source\Runtime\MeshDescription\Public\MeshDescription.h:242]
UnrealEditor_MeshConversion!FDynamicMeshToMeshDescription::Convert_NoSharedInstances() [D:\build++UE5\Sync\Engine\Source\Runtime\MeshConversion\Private\DynamicMeshToMeshDescription.cpp:900]
UnrealEditor_ModelingComponents!UE::ToolTarget::CommitMeshDescriptionUpdateViaDynamicMesh() [D:\build++UE5\Sync\Engine\Plugins\Runtime\MeshModelingToolset\Source\ModelingComponents\Private\ModelingToolTargetUtil.cpp:315]
UnrealEditor_MeshModelingToolsExp!UPlaneCutTool::GenerateAsset() [D:\build++UE5\Sync\Engine\Plugins\Experimental\MeshModelingToolsetExp\Source\MeshModelingToolsExp\Private\PlaneCutTool.cpp:437]
UnrealEditor_MeshModelingToolsExp!UPlaneCutTool::OnShutdown() [D:\build++UE5\Sync\Engine\Plugins\Experimental\MeshModelingToolsetExp\Source\MeshModelingToolsExp\Private\PlaneCutTool.cpp:261]
UnrealEditor_ModelingComponents!UMultiSelectionMeshEditingTool::Shutdown() [D:\build++UE5\Sync\Engine\Plugins\Runtime\MeshModelingToolset\Source\ModelingComponents\Private\BaseTools\MultiSelectionMeshEditingTool.cpp:57]
UnrealEditor_InteractiveToolsFramework!UInteractiveToolManager::DeactivateToolInternal() [D:\build++UE5\Sync\Engine\Source\Runtime\InteractiveToolsFramework\Private\InteractiveToolManager.cpp:277]
UnrealEditor_InteractiveToolsFramework!UInteractiveToolManager::DeactivateTool() [D:\build++UE5\Sync\Engine\Source\Runtime\InteractiveToolsFramework\Private\InteractiveToolManager.cpp:259]
UnrealEditor_EditorInteractiveToolsFramework!UEditorInteractiveToolsContext::DeactivateActiveTool() [D:\build++UE5\Sync\Engine\Source\Editor\Experimental\EditorInteractiveToolsFramework\Private\EdModeInteractiveToolsContext.cpp:773]
UnrealEditor_EditorInteractiveToolsFramework!UEditorInteractiveToolsContext::Tick() [D:\build++UE5\Sync\Engine\Source\Editor\Experimental\EditorInteractiveToolsFramework\Private\EdModeInteractiveToolsContext.cpp:451]
UnrealEditor_EditorInteractiveToolsFramework!UModeManagerInteractiveToolsContext::Tick() [D:\build++UE5\Sync\Engine\Source\Editor\Experimental\EditorInteractiveToolsFramework\Private\EdModeInteractiveToolsContext.cpp:877]
UnrealEditor_UnrealEd!FEditorModeTools::Tick() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorModeManager.cpp:1257]
UnrealEditor_UnrealEd!FEditorViewportClient::Tick() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorViewportClient.cpp:1478]
UnrealEditor_UnrealEd!FLevelEditorViewportClient::Tick() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\LevelEditorViewport.cpp:2514]
UnrealEditor_UnrealEd!UEditorEngine::Tick() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorEngine.cpp:2020]
UnrealEditor_UnrealEd!UUnrealEdEngine::Tick() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\UnrealEdEngine.cpp:531]
UnrealEditor!FEngineLoop::Tick() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:5825]
UnrealEditor!GuardedMain() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:188]
UnrealEditor!GuardedMainWrapper() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:118]
UnrealEditor!LaunchWindowsStartup() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:258]
UnrealEditor!WinMain() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:298]
UnrealEditor!__scrt_common_main_seh() [D:\a_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]

This is a fairly common crash error from it, I’ve attempted simplification of the mesh, however it doesnt really matter. It seems to be having issues when Attempting to access the container that has the BitArray. Not all meshes have this issue, now WITHOUT running a mirror pass on these particular megascans, Plane cut has no issues.

[hexen1337]

Found some work arounds, However its still a very painful process. This tool has some serious problems accessing memory.

[hexen1337]

Alright so i figured out what the problem was, My 13900kf was being Destroyed by the motherboard and was actually dying, which also killed my RAM which was the cause of the issues, The dying of the CPU/RAM (bad default bios settings killed the CPU/RAM after 1.5 years) since then switched to a 14900kf, new ram, new Mobo brand and changed all Bios settings to recommended settings from intel and i have no issues. Never had a bios destroy an entire setup before, but that was the cause!

Hardware failure.