Steps to reproduce:

1. Create a project
2. Window -> Package Management -> Package Manager
3. Click “+” and select “Create package”
4. Enter package name and click “Create”
5. Select newly created package for it to appear in Inspector window
6. Close the "Package Manager" window
7. Click the “Edit” button in the “Inspector” window
8. Delete all the data from all the fields
9. Click the mouse in the “Hierarchy” or “Project” window
10. Verify that you get the “Inspector - Unsaved Changes Detected” warning
11. Click “Save” and observe the result

Actual results: Editor crashes

Expected results: Editor should not crash. It should stay open.

Reproducible with versions: 6000.3.0a3

Not reproducible with versions: -

Can’t test with versions: 6000.3.0a2 as package creation functionality landed just in 6000.3.0a3

Tested on (OS): M1 Max - Sequoia 15.5, Windows 11

Note 1:
First few lines of stack trace:
{code:java}
0x00007FF94F9A9B1F (Unity) WriteObjectToVector
0x00007FF950FB71D0 (Unity) CreateOrReloadInspectorCopy
0x00007FF94EDF4031 (Unity) AssetImporterEditor_CUSTOM_CreateOrReloadInspectorCopy
0x000001AD3B7E4F7D (Mono JIT Code) (wrapper managed-to-native) UnityEditor.AssetImporters.AssetImporterEditor:CreateOrReloadInspectorCopy_Injected (int,intptr) {code}
Note 2: One more crash case is listed in the "Comments" section.