Reproduction steps:
1. Open the attached "Splined.zip" project
2. Select the "Spline Buildings" GameObject
3. In the Scene view enable Spline Active Context
4. Duplicate
5. Undo
6. Observe the crash

Reproducible with: 1.0.0 (2022.1.0b12, 2022.2.0a8)
Not reproducible with: 1.0.0-pre.9 (2022.2.0a7)
Could not test with: 1.0.0-pre.8 (2019.4.37f1, 2020.3.32f1, 2021.2.16f1) (errors and pink textures after downgrade)

First few stack frames:
0x00007ff631a3b2c6 (Unity) DestroyObjectHighLevel_Internal
0x00007ff631a3ae94 (Unity) DestroyObjectHighLevel
0x00007ff631d9b57e (Unity) Scripting::DestroyObjectFromScriptingImmediate
0x00007ff630f13a34 (Unity) Object_CUSTOM_DestroyImmediate
0x0000016dc7083d25 (Mono JIT Code) (wrapper managed-to-native) UnityEngine.Object:DestroyImmediate (UnityEngine.Object,bool)
0x0000016dc7083c73 (Mono JIT Code) UnityEngine.Object:DestroyImmediate (UnityEngine.Object)
0x0000016df0f87f83 (Mono JIT Code) [SplineInstantiate.cs:538] SplineInstantiate:TryClearCache ()
0x0000016b07ca4dbb (Mono JIT Code) [SplineInstantiate.cs:511] SplineInstantiate:Clear ()
0x0000016b07ca4cfb (Mono JIT Code) [SplineInstantiate.cs:428] SplineInstantiate:OnDestroy ()