I've had the same problem.
Easy way is to export your library to an xml.
Then open the xml in an editor.
Search and replace the faulty path.
Import the xml and all should be changed.
I'm encountering this issue as well, only I do not know how to export the library to an xml. Would you be able to help with that? I'm running PS 13.1 disconnected.
When you're using an disconnected cell you cannot export an xml. That is a database action.
Having said that/
the psz file is nothing but a zip file. Inside it you will find an xml.
Make a copy of your psz an give it a try.