I’m having this problem too on 4.8.3. Steps to reproduce:
Create a couchknights project. Create a directory named “CouchKnightsMigrate”.
Move all the other folders into “CouchKnightsMigrate”. Save all. Reopen the project, and you get all these errors:
Right clicking Content -> fix up redirectors fails as well:
Trying a few folders at a time fails in much the same way.