I have a world-partition project, copied from 5.3 to 5.4.3 that has some quirks in display in one level ( Viewport becomes unusable after moving cursor - General / Feedback & Requests - Epic Developer Community Forums (unrealengine.com) but no other problems. I usually have one region opened , done quite a lot of edits but it all worked.
However, after the update to Unreal 5.4.4, opening that same project caused a crash of UnrealEditor with the message:
Error: Assertion failed: ScratchBufferRequiredSize + ScratchBufferOffset <= ScratchBufferSize [File:D:\build\++UE5\Sync\Engine\Source\Runtime\D3D12RHI\Private\D3D12RayTracing.cpp] [Line: 3934]
[2024.09.19-19.03.32:963][691]LogWindows: Error: BLAS scratch buffer size is 10081422919936 bytes with offset 662558289920 (1349888 bytes available), but the build requires 1354496 bytes.
No change was made to the project!
I have the original 5.3.2 version at hand so I re-did the migration from 5.3.2 to 5.4.4, opened that project and again, after the project was loaded, Unreal crashed again:
> Assertion failed: ScratchBufferRequiredSize + ScratchBufferOffset <= ScratchBufferSize [File:D:\build\++UE5\Sync\Engine\Source\Runtime\D3D12RHI\Private\D3D12RayTracing.cpp] [Line: 3934]
> [2024.09.19-20.16.08:673][717]LogWindows: Error: BLAS scratch buffer size is 6425849810432 bytes with offset 395715042560 (2314988056832 bytes available), but the build requires 1298944 bytes.
The end of the logfile is (apart from the counters) the same:
2024.09.19-19.03.31:425][691]LogWindows: Error: appError called: Assertion failed: ScratchBufferRequiredSize + ScratchBufferOffset <= ScratchBufferSize [File:D:\build++UE5\Sync\Engine\Source\Runtime\D3D12RHI\Private\D3D12RayTracing.cpp] [Line: 3934]
BLAS scratch buffer size is 10081422919936 bytes with offset 662558289920 (1349888 bytes available), but the build requires 1354496 bytes.[2024.09.19-19.03.31:427][691]LogWindows: Windows GetLastError: The operation completed successfully. (0) [2024.09.19-19.03.32:962][691]LogRHI: Error: Breadcrumbs 'RHIThread' [2024.09.19-19.03.32:962][691]LogThreadingWindows: Error: Runnable thread RHIThread crashed. [2024.09.19-19.03.32:963][691]LogWindows: Error: === Critical error: === [2024.09.19-19.03.32:963][691]LogWindows: Error: [2024.09.19-19.03.32:963][691]LogWindows: Error: Assertion failed: ScratchBufferRequiredSize + ScratchBufferOffset <= ScratchBufferSize [File:D:\build\++UE5\Sync\Engine\Source\Runtime\D3D12RHI\Private\D3D12RayTracing.cpp] [Line: 3934] [2024.09.19-19.03.32:963][691]LogWindows: Error: BLAS scratch buffer size is 10081422919936 bytes with offset 662558289920 (1349888 bytes available), but the build requires 1354496 bytes. [2024.09.19-19.03.32:963][691]LogWindows: Error: [2024.09.19-19.03.32:963][691]LogWindows: Error: [2024.09.19-19.03.32:963][691]LogWindows: Error: [Callstack] 0x00007ffe571ccfa7 UnrealEditor-D3D12RHI.dll!UnknownFunction [] [2024.09.19-19.03.32:963][691]LogWindows: Error: [Callstack] 0x00007ffee101f00d UnrealEditor-RHI.dll!UnknownFunction [] [2024.09.19-19.03.32:963][691]LogWindows: Error: [Callstack] 0x00007ffee102266f UnrealEditor-RHI.dll!UnknownFunction [] [2024.09.19-19.03.32:963][691]LogWindows: Error: [Callstack] 0x00007ffee10203b6 UnrealEditor-RHI.dll!UnknownFunction [] [2024.09.19-19.03.32:963][691]LogWindows: Error: [Callstack] 0x00007ffee100b4db UnrealEditor-RHI.dll!UnknownFunction [] [2024.09.19-19.03.32:963][691]LogWindows: Error: [Callstack] 0x00007ffee102606f UnrealEditor-RHI.dll!UnknownFunction [] [2024.09.19-19.03.32:963][691]LogWindows: Error: [Callstack] 0x00007ffe99eeb88a UnrealEditor-Core.dll!UnknownFunction [] [2024.09.19-19.03.32:963][691]LogWindows: Error: [Callstack] 0x00007ffe99eebf2e UnrealEditor-Core.dll!UnknownFunction [] [2024.09.19-19.03.32:963][691]LogWindows: Error: [Callstack] 0x00007ffec4a0641d UnrealEditor-RenderCore.dll!UnknownFunction [] [2024.09.19-19.03.32:963][691]LogWindows: Error: [Callstack] 0x00007ffe9a52c93d UnrealEditor-Core.dll!UnknownFunction [] [2024.09.19-19.03.32:963][691]LogWindows: Error: [Callstack] 0x00007ffe9a5202b7 UnrealEditor-Core.dll!UnknownFunction [] [2024.09.19-19.03.32:963][691]LogWindows: Error: [Callstack] 0x00007fff1d18257d KERNEL32.DLL!UnknownFunction [] [2024.09.19-19.03.32:963][691]LogWindows: Error: [2024.09.19-19.03.32:963][691]LogWindows: Error: Crash in runnable thread RHIThread [2024.09.19-19.03.32:989][691]LogExit: Executing StaticShutdownAfterError [2024.09.19-19.03.33:320][691]LogWindows: FPlatformMisc::RequestExit(1, FRunnableThreadWin::GuardedRun.ExceptionHandler) [2024.09.19-19.03.33:320][691]LogWindows: FPlatformMisc::RequestExitWithStatus(1, 3, FRunnableThreadWin::GuardedRun.ExceptionHandler) [2024.09.19-19.03.33:320][691]LogCore: Engine exit requested (reason: Win RequestExit)
Biggest problem now is that I cannot undo the latest update and revert to 5.4.3 - that I could use.