How to reproduce:
1. Open the attached “IN-128772” project
2. Open the “GeoTests” scene
3. Wait for ~1 - 2 minutes
4. Observe the crash

Reproducible with: 6000.3.0a3, 6000.3.9f1, 6000.4.0b9, 6000.5.0a7
Not reproducible with: 6000.0.68f1, 6000.3.0a2

Reproduced on: Windows 11
Not reproduced on: No other environment tested

Notes:
- It’s best to re-extract the project each time as the issue can be inconsistent
- The issue does not occur after deleting the “MapStructureTester” script (Scripts > PCG > MapGenerator)

First few lines of the stack trace:
0x00007FFE38548521 (Unity) memcpy
0x00007FFE34D71DA5 (Unity) UnsafeUtility_CUSTOM_MemCpy
0x00000265BAA6F348 (Mono JIT Code) (wrapper managed-to-native) Unity.Collections.LowLevel.Unsafe.UnsafeUtility:MemCpy (void,void,long)
0x00000265BAEB0CE3 (Mono JIT Code) [.\Library\PackageCache\com.unity.collections@aea9d3bd5e19\Unity.Collections\UnsafeList.cs:364] Unity.Collections.LowLevel.Unsafe.UnsafeList`1<MapGenerator.CellTerrainData>:ResizeExact<Unity.Collections.AllocatorManager/AllocatorHandle> (Unity.Collections.AllocatorManager/AllocatorHandle&,int)
0x00000265BAEB0BB3 (Mono JIT Code) [.\Library\PackageCache\com.unity.collections@aea9d3bd5e19\Unity.Collections\UnsafeList.cs:390] Unity.Collections.LowLevel.Unsafe.UnsafeList`1<MapGenerator.CellTerrainData>:SetCapacity<Unity.Collections.AllocatorManager/AllocatorHandle> (Unity.Collections.AllocatorManager/AllocatorHandle&,int)