My iCloud photo library has stopped syncing with my Mac and I’m assuming this coincides with me getting an error message in iCloud settings saying “this Mac can’t connect with iCloud because of a problem with (email address)”.
I want to try logging out and back into iCloud, but am concerned about any unintended consequences as I’ve heard too many horror stories when fixing iCloud issues. Do I need to prepare for anything or be concerned?
I have current TimeMachine and Backblaze backups, so that’s done. Also, I use iCloud to log into my user account on my Mac. If I log out of iCloud and restart the Mac, am I going to be locked out of the machine?
I had the same issue this week. Did a quick copy of the photo library and logged out and back in to icloud. From then on everything seems to work as normal.
I vouch for signing out and into iCloud. That often fix iCloud issues, not cause them.
Your user should be safe, you should be able to use the same password to sign in. However, I always recommend to create a new, empty admin user account (not tied to an iCloud account). With this you can reset the password to the other admin account.
Rebuilding the library is also a good step, as JKoopmans mentions.