Unable to Switch Users D;

Once I am logged into admin, ever since I downloaded the new update last night, I am unable to switch to any other users. Neither by using "fast user switching," by logging out of the current user, which should bring me to the list of users nor by clicking, "Lock screen," which has a button that I am able to select that should allow me to "Switch users."

With every instance, it just defaults straight back to only allow me to log back into admin, by using my PIN.

Several times, it does show other users briefly, I try to click on an alternate user quickly, but it just flashes the list of users before defaulting back to only allowing me the option to log in to Admin by inputting my PIN.

It's a pain in the butt. I have different profiles for work, school, etc. I am unable to access anything but my personal Admin account.

So far, no cigar. The problem is persisting in Safe Mode.

However, following the subsequent advice on the link you provided, I have just updated several apps that were out of date.

Interestingly, most of them required my admin password to update, but one required a different user's password. (A user I have been trying to and have been unable to access.)

The app updates have just finished. I will try again and let you know the outcome!

Alas, the problem still persists.

In both safe and normal boot.

I guess I must now attempt the final recommendation in the link you provided:

"reinstall MacOS"

I did initiate the update from another user's profile, rather than the admin's.

I wonder if, for some reason, that was part of the problem.

Although I can't imagine why it would be.

About to follow instructions to reinstall macOS.

I will keep you updated.

(This wouldn't wipe my drive, right?!)

I reinstalled the MacOS several times.

I haven't been able to figure out how to reinstall the OS it had originally.

Still, the issue persists.

I was able to log in to another User briefly and gave myself enough time to share all of the content from that profile with the admin.

Before I was promptly locked out again.

I am about to attempt another reinstall of the OS, and then, after it is complete, and boots up, I will try shutting the system down and running it in Safe Mode, and try to access the other user profiles that way, first. See what happens.