Photos stuck at "Updating Library 100% Complete" after High Sierra upgrade
Photos app stuck at "Updating Library 100% Complete" for going on 5 hours, after High Sierra upgrade. Option to Quit app is greyed out. Cannot use or access any app user interface or features. Just stuck on the last slide of the "Have Fun With Photos" tour. Cannot restart MacBook because getting message: "Cannot quit Photos while it is creating or opening a library" and then "Photos interrupted restart." Please advise. P.s. I DO NOT use iCloud Photo Library.
MacBook Pro with Retina display, macOS High Sierra (10.13), null