How to reproduce:
1. Open the attached “IN-128216” project
2. Right click the “test” Asset and select "Reimport"
3. Take note of the confirmation message in the Console window
4. Right click any asset and select "Reimport All"
5. Observe the result

Actual result: No errors occur in the Console window
Expected result: A “prefab is null” error occurs

Reproducible with: 6000.0.0b14, 6000.0.65f1, 6000.3.3f1, 6000.4.0b3, 6000.5.0a4
Could not test with: 6000.0.0b13 (no Serialized Member in the Inspector of the “test” Asset)

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