Question: Photos library could not be opened
Attempting to repair Photos library by holding down Option/Command when selecting Photos.
After choosing to repair, I input my login password to begin the process, which gets to 5%, when a window appears:
If I quit and begin the repair process again, I obtain the same result.
This may be related to my synchronizing (Synchronize Pro! X) the .photoslibrary files in my user accounts on two separate Macs (both running 10.13.3).
Mac mini, macOS High Sierra (10.13.3), Late 2012 Quad 2.6GHz i7