This may be a bug or just another of Plastic SCM's pain points:
Unity 2021.2.8f1 + Version Control 1.15.16
Steps to reproduce:
1. CTRL-D to duplicate a prefab (Project window)
2. Rename that prefab (Project window)
3. Double-click the prefab to edit it
4. Delete something that's in the prefab's hierarchy
5. Save
Result: Plastic SCM plugin complains that it can't find the original duplicated file (the one created in step 1)
@marie-unity
Unity 2021.2.8f1 + Version Control 1.15.16
Steps to reproduce:
1. CTRL-D to duplicate a prefab (Project window)
2. Rename that prefab (Project window)
3. Double-click the prefab to edit it
4. Delete something that's in the prefab's hierarchy
5. Save
Result: Plastic SCM plugin complains that it can't find the original duplicated file (the one created in step 1)
@marie-unity