Cannot open level after upgrade to 5.5

[WillemGr]

My project, started in 5.4, has been migrated to 5.5 and further development went on in that version. At some point(update to 5.5.1, or 5.5.2? ) I got errors on generation of PCG-volumes or spline-based PCG’s, as described in InstanceId must fit in 24 bits. - General / Feedback & Requests - Epic Developer Community Forums.
I deleted the PCG’s that caused the problem, after that, things got worse, probably after the update to 5.5.2: opening the level crashes with the same message:

Assertion failed: InstanceDesc.InstanceId <= 0xFFFFFF [File:D:\build++UE5\Sync\Engine\Source\Runtime\Renderer\Private\RayTracing\RayTracingInstanceBufferUtil.cpp] [Line: 312]
InstanceId must fit in 24 bits.

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

Of course, I get messages on opening, but still this message comes up. Given the message it mist be some instance ID but I have no clue which one.

I tried disabling raytracing but that didn’t help.
Older levels open just fine, it’s just this one that causes poblems.

Migrating this level to 5.4 crashes too:

Assertion failed: WorldSettings != nullptr [File:D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\Level.cpp] [Line: 3238]
/Game/Levels/Main4_DEADFROMMIGRATION_2.Main4:PersistentLevel

UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_PCG
UnrealEditor_PCG
UnrealEditor_PCG
UnrealEditor_PCG
UnrealEditor_PCG
UnrealEditor_PCG
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_AssetTools
UnrealEditor_AssetTools
UnrealEditor_AssetTools
UnrealEditor_AssetTools
UnrealEditor_AssetTools
UnrealEditor_AssetTools
UnrealEditor_Slate
UnrealEditor_Slate
UnrealEditor_Slate
UnrealEditor_Slate
UnrealEditor_Slate
UnrealEditor_Slate
UnrealEditor_Slate
UnrealEditor_ApplicationCore
UnrealEditor_ApplicationCore
UnrealEditor_ApplicationCore
UnrealEditor_ApplicationCore
user32
user32
UnrealEditor_ApplicationCore
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
kernel32
ntdll

What causes this error - how can I find out what causes the error and how can I reopen the level?

[brs-sebascova]

Hello there @WillemGr!

From your provided logs, your scenario could fall either in drivers or engine issues. Let’s take a few paths to resolution:

• Please update your nVIDIA drivers, make sure you are picking the “Clean Installation” option, as well as going for the “Developer” drivers, as these have more stable settings for engine work.
  

  

• Since your current project was on a previous version of Unreal, and its now updated to 5.5, rendering settings from the previous build could be causing a conflict. In order to reset them, please search for DefaultGame.ini file, open it wirh a notepad, and delete all settings under the header [/Script/Engine.RendererSettings]

• To rule out hardware issues, in Unreal Engine, adjust your values for engine scalabillty, to ensure your equipment is not being exerted.
  

  

• Test disabling Hardware Raytracing from the engine
  

  

• Please make sure that no RTSS or overlocking are enabled for your video card while working on the engine.

• Uncheck all SM5 in the project settings (Project Settings → Platforms → Windows).

• Disable motion blur in postprocessing settings.

• Remove and reinstall any mesh packs recently added to your UE.

• Additionally, there are two settings to test in nVidia control panel: Go to Settings, and under Features → Overlay, disable the “Game filters and Photo Mode” option. After that, click on “Manage 3D Settings” in the settings menu on the left, go to Monitor Technology and select “Fixed Rate”. With these changes applied, please restart UE5.