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.
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.
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.
nvidia driver: I use the studio driver already, installed the latest update as triggered by nvidia app…I
Scalability set to Cinematic: No change
Disable hardware tracing: done - but it was needed for lighting… So no.
Use default settings on the (ASUS) video card - no RTSS or overlocking (Never had issues before, and other levels just open fine…)
No post-processing volume in the level - done in project settings.
No new mesh packs were added in this level, just a number of spline-based PCG’s - and these seem to trigger the error!!!
Settings now is in new nvidia app , changed it there. but I didn’t see any Monitor Technology in app or Nvidia control panel…
None of these made the difference . Next, I found that Lumen and MegaLights use raytracing, you have to disable these first before disabling hardware raytracing. (MegaLights is experimental, and I have a lot of lights in my scene - is it switched on in the migration to 5.5 ??? I didn;t enable it!!)
Now the level does start - though VERY slow… But it gave me the opportunity to remove the PCG’s that seem to cause problems.
I had deleted the assets in the content browser using another level, so that may have cause the next error when saving the level:
Assertion failed: InExpectedDataPtr == &InternalData [File:D:\build++UE5\Sync\Engine\Source\Runtime\TypedElementFramework\Public\Elements\Framework\TypedElementData.h] [Line: 558]
Internal data pointer did not match the expected value! Does this handle belong to a different element registry?
