Interesting. I’ll confess that when I upgraded from Catalina to Big Sur, I did so after logging into my secondary admin account, and the first boot after the upgrade was totally normal. I just didn’t want to risk problems with that major upgrade.
Just to note, these authentication failures are not the end of the world. If I forget to initiate the update from a secondary admin account, I just have to cancel a lot of authentication dialogs and restart again for everything to be normal.
But I still feel like Charlie Brown (or is it the football?) every time I forget and have the problem happen again.
But alas, it made no difference when I updated to 11.2.2.
It’s very hard to test new theories when I have to wait for another minor macOS update to roll in for the next test. Any thoughts on what I should try for 11.2.3?
After review this thread again, I am reminded of weird problems like Preferences which would not open for the primary admin account but would for others. To recover function on this primary account, I renamed the home folder, causing a new home folder tree to be created when the problem account logged in again. Subsequently and with tedious and painstaking effort, copied data files, iTunes libraries and the like and carefully selected Library contents. The client was impressed and happy to have normal functions.
It would be somewhat more difficult to do this today as Apple has taken to stuffing user data into ~/Library, Books being an obvious culprit.