I’m having this problem as well. Although, I have 0 nanite meshes. The level loads but as soon as I click on the viewport it crashes.
Fatal error: [File:D:\build++UE5\Sync\Engine\Source\Runtime\RenderCore\Private\RenderingThread.cpp] [Line: 934]
Rendering thread exception:
Assertion failed: NumSceneInstancesPo2 <= (1 << 24) [File:D:\build++UE5\Sync\Engine\Source\Runtime\Renderer\Private\Nanite\NaniteCullRaster.cpp] [Line: 1345]
0x00007ffe13497b6c UnrealEditor-Renderer.dll!UnknownFunction []
0x00007ffe1394ef7e UnrealEditor-Renderer.dll!UnknownFunction []
0x00007ffe13951d14 UnrealEditor-Renderer.dll!UnknownFunction []
0x00007ffe139203a2 UnrealEditor-Renderer.dll!UnknownFunction []
0x00007ffe139396ba UnrealEditor-Renderer.dll!UnknownFunction []
0x00007ffe139411fa UnrealEditor-Renderer.dll!UnknownFunction []
0x00007ffe383e3a9d UnrealEditor-Core.dll!UnknownFunction []
0x00007ffe383e3f3e UnrealEditor-Core.dll!UnknownFunction []
0x00007ffe383e42e1 UnrealEditor-Core.dll!UnknownFunction []
0x00007ffe7b2d976b UnrealEditor-RenderCore.dll!UnknownFunction []
0x00007ffe7b2dd158 UnrealEditor-RenderCore.dll!UnknownFunction []
0x00007ffe38ab7a2b UnrealEditor-Core.dll!UnknownFunction []
0x00007ffe38ab0a90 UnrealEditor-Core.dll!UnknownFunction []
0x00007ffea1d67034 KERNEL32.DLL!UnknownFunction []
0x00007ffea33c26a1 ntdll.dll!UnknownFunction []