Reproduction steps:
1. Open the attached project “ReproProject”
2. Open the scene “SampleScene“
3. Navigate to Window → Rendering → Occlusion culling
4. In the opened window, click on the “Bake“ button located in the bottom right corner
5. Wait for approximately 10 seconds
6. Observe the crash

Reproducible in: 2023.1.0a1, 6000.0.68f1, 6000.3.10f1, 6000.4.0b10, 6000.5.0a7

Reproducible on: Windows 11
Not reproducible on: No other environments tested

Note:
- In the project, the script “OcclusionCrashRepro.cs” adds Tools → Generate 250k Occludes, which allows to generate 250k occludes for a current scene
- The scene “SampleScene“ contains 250 thousand cubes (PrimitiveType.Cube)

First few lines of the stacktrace:

0x00007FFE9821E6F7 (Unity) Umbra::PortalCuller::init
0x00007FFE98224C11 (Unity) Umbra::Query::queryPortalVisibility
0x00007FFE9823076F (Unity) UmbraModule::QueryPortalVisibility
0x00007FFE9AD38D40 (Unity) QueryPortalVisibilityJob
0x00007FFE9ADF7858 (Unity) ujob_execute_job