photos cannot find the Systems photo library

After the update this morning, photos can no longer find the photo library (libraries).... I can see the library, I can select the library but photos can't find it..
Even if I get photos to create a new library, it can't find that one either..

I had this problem before and eventually it was fixed after 3 or 4 further beta updates...

My photos / "Pictures" directory is on an external Pegasus RAID drive.




2013 Mac Pro,

MacOS 10.15.5 beta.