What exactly happens, when you try to open the library?
Ans:
1 - As soon as I finished the OS update.
2 - I restarted the Mac mini again. I try to open library straight after it started up. Failed to open photo library.
Do you get an error message? If yes, which message?
Ans:
The library could not be opened.
The Photos was unable to open the library “Photos Library 2002”. (4302)
Quit or Open Other
Then
No matter I create a new photo library or open an old one. Fail and the message is:
PHPhotosErrorInvalidState
Where is your Photos Library stored? On an external volume or in your Pictures folder?
Ans:
External volume and it was fine before OS update
What happens when you try to create a new library? Where does it go wrong?
Ans:
No matter I create a new photo library or open an old one. Fail and the message is:
PHPhotosErrorInvalidState
Are you launching Photos by clicking the the Photos icon in Applications, or are you using an alias on the Desktop or in the Dock?
Ans:
I always launch Photos by clicking the icon in the Dock.
Try to launch Photos by clicking the app directly in the Applications folder, so you can be sure to launch the version installed by the system upgrade and not an outdated link.
Ans:
I just tried the photos icon in Applications. Again, fail same way.
Very regretted that I never use the time machine. Would be very appreciated if some advise or instruction could be given. I stored my last 10 years of photos in the Photos!