UE 5.1 crashes on opening levels for several times, then opens normally. NaniteRayTracing.cpp

Hello,

My editor (UE 5.1) keeps crashing on opening some (most) of the levels. It happens for few times in a row, then it opens normally. It seems to be connected to the Nanite, RT and DX12. Tried different solutions, found in the web (reinstall the engine, different GPU drivers, reset graphic options in Nvidia panel to defaults, replaced UnrealEditor-D3D12RHI with some adjusted version, etc), but none of them helped.
My spec:

  • RTX 4090
  • i9 13900K
  • 64GB DDR5 ram
LoginId:a35384524e0da9000bc21aa1b1d56283
EpicAccountId:bb9c2565a6dd43808db4b760c7fae993

Assertion failed: ScheduledBuilds.IsEmpty() [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Renderer\Private\Nanite\NaniteRayTracing.cpp] [Line: 531] Scheduled builds were not dispacthed last frame.

UnrealEditor_Renderer
UnrealEditor_Renderer
UnrealEditor_Renderer
UnrealEditor_Renderer
UnrealEditor_Renderer
UnrealEditor_Renderer
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_RenderCore
UnrealEditor_RenderCore
UnrealEditor_Core
UnrealEditor_Core
kernel32
ntdll

Anyone?

1 Like

I believe this is related to using the full nanite mesh instead of the fallback mesh for raytracing/path tracing. Try using the console command r.RayTracing.Nanite.Mode 0 to use the fallback mesh instead.

I recently have samiliar issue, seems 13900k + 4090 is a bad combination some how. But I kinda found a work around, goto th Intel website and download “Extreme Tuning Ulitily”, then set p-core and e-core down a little bit, and the crashes and blue screens never showed again. Just give it a try.