I recently had to reboot my computer, and when it finished booting my account was gone (it was not showing in the log in screen)! I got onto the admin account and found that although the user was not deleted, there are a lot of red minus signs:
How do I fix this?
I noticed that it does not work quite like what is described here:
https://support.apple.com/kb/PH22002?locale=en_US
It's more like this:
https://discussions.apple.com/thread/4171806?start=0&tstart=0
I am running OS X El Capitan 10.11.3
Best Answer
Log-in as admin user and open Terminal. Then enter
Replace lost_username by the short name of the "hidden" or "lost" user.
If the user is still there check if the account is hidden:
If you get the following response: No such key: IsHidden you have a real problem. If it yields: dsAttrTypeNative:IsHidden: 1 your user is just hidden.
Unhide your user with:
or delete the key with
You have to reboot after entering either of the last two commands to unhide the account.
If you get DS Error: -14136 (eDSRecordNotFound) after entering the first command your user was deleted in the directory nodes.
Quick and dirty fix:
List the users' UniqueIDs with:
Usually the first account created after installing OS X gets the 501, the second 502 and so on. Check for gaps (e.g. 502 is missing).
Rename (shorten) the abandoned user folder. Create a new user with the old user name (lost_username) and the old password. Check the UniqueID of the new user:
Compare this UniqueID with the missing one. If they aren't the same, change the UniqueID of the newly created user to the missing one:
Remove the newly created user folder (with the name lost_username). Rename the previously renamed (old and full with data) user folder to lost_username.
Log-in as lost_username.