We've been having issues with a few just getting past the login screen for mac minis in our office. Basically, we just enter the the password for a standard or admin account and it would do the loading animation for a few seconds and then the screen will go black and all of a sudden we are back at the login screen. We will try to log in again and again with no luck. For one computer, this happened so we just put it aside and come back a few hours, we are able to log in normally. If anyone has any insight on what could be the issue or has dealt with this and found a solution, any help would be appreciated.