Reproduction steps:
1. Open the attached project "CrashRepro"
2. Add a new Empty Sub Scene (Right-click in the Hierarchy window > New Sub Scene > Empty Scene…)
3. Add an empty GameObject to the subscene
4. Add Mesh filter and Mesh renderer components to the empty GameObject
5. Set the Mesh Filter component Mesh to “Cube“

Expected result: Mesh is rendered
Actual result: Editor crashes

Reproducible with: 1.2.0 (2022.3.31f1), 1.2.1 (2022.3.31f1)
Not reproducible with: 1.1.16 (2023.1.0a11), 1.2.0 (6000.0.4f1), 1.2.1 (6000.0.4f1)
Couldn’t test with: 1.1.16 (2023.1.0a1 - 2023.1.0a10) (Couldn’t add a subscene), 1.2.1 (2023.1.0a11) - Console errors

Reproducible on: Windows 10
Not reproducible on: macOS 14.5 Sonoma (Intel)

Notes:
Does not reproduce on a new project
Steps 4 and 5 are interchangeable, the order does not matter

First few lines of stack trace:
{noformat}
0x00007ff72b8240e0 (Unity) BatchRendererGroup_CUSTOM_RegisterMaterial_Injected
0x0000019d41bcbf5f (Mono JIT Code) (wrapper managed-to-native) UnityEngine.Rendering.BatchRendererGroup:RegisterMaterial_Injected (UnityEngine.Rendering.BatchRendererGroup,UnityEngine.Material,UnityEngine.Rendering.BatchMaterialID&)
0x0000019d41bcbe73 (Mono JIT Code) UnityEngine.Rendering.BatchRendererGroup:RegisterMaterial (UnityEngine.Material)
0x0000019d41bcbdf3 (Mono JIT Code) Unity.Rendering.EntitiesGraphicsSystem:RegisterMaterial (UnityEngine.Material) (at ./Library/PackageCache/com.unity.entities.graphics@1.2.1/Unity.Entities.Graphics/EntitiesGraphicsSystem.cs:2592)
0x0000019d4187e113 (Mono JIT Code) Unity.Rendering.RegisterMaterialsAndMeshesSystem:RegisterMaterialsAndMeshes (Unity.Jobs.JobHandle) (at ./Library/PackageCache/com.unity.entities.graphics@1.2.1/Unity.Entities.Graphics/EntitiesGraphicsSystem.cs:542)
0x0000019d4187cefb (Mono JIT Code) Unity.Rendering.RegisterMaterialsAndMeshesSystem:OnUpdate () (at ./Library/PackageCache/com.unity.entities.graphics@1.2.1/Unity.Entities.Graphics/EntitiesGraphicsSystem.cs:384)
0x0000019cf4e1124b (Mono JIT Code) Unity.Entities.SystemBase:Update () (at ./Library/PackageCache/com.unity.entities@1.2.1/Unity.Entities/SystemBase.cs:420){noformat}