There is one troubleshooting step that OS X shares with the classic Mac OS, removing preference files. But on OS X there are TWO folders:
/Library/Preferences and ~/Library/Preferences
--The latter being in your user/home folder--
Since the issue doesn't exist under another logon it is specific to that user folder. SO there is something specific to that user that is causing the problem. This takes the /Library/Preferences folder out of consideration for troubleshooting preferences. The first thing I would do is use a utility like Onyx to verify and clean the system. This includes verifying preferences files. After that rename the ~/Library/Preferences folder to something like
~/Library/Preferences-old
You'll probably have to do that in Terminal and use sudo as those files are owned by another user on the system. then create a new ~/Library/Preferences folder and reboot.
If you can now log into that account it is a simple (HAH!) matter of putting preferences files in the new Preferences folder and rebooting till you find which one it is.
No guarantee, though, that it is a preference file, it could be a startup item. So do the same thing with the ~/Library/LaunchAgents folder.
The other thing to consider is that it might be easier to just create a new user folder. Copy the things you need out of the old user folder and delete the old user. That could save you a lot of troubleshooting time. It would be my preferred way of doing it (after running Onyx) as I care less about what happened than just finding a fix that gets me up and running more quickly.
I tried everything suggested many times and have finally had to just re-image my machine. there was apparently something running on my laptop that was attempting to constantly login but, neither I or our corporate Mac support team could figure it out. I have not had any issues since re-imaging.
Thank you for all the suggestions!
Best Answer
I have just encountered this issue. The way that worked for me is to create a new administrator as described in How can I get admin access to a Mac without knowing the current password?, then use the new administrator to reset the original accounts password. Then I was able to log into the original account.
Before this method, I have tried
resetting pram and smc
running disk check from recovery mode
unsuccessfully trying to modify the encrypted apfs to decrypt it (it seems like encrypted is default)
resetting password of my original accounts from recovery mode
changing the password to the login keychain in terminal in recovery mode in case my password on the keychain wasn't updated along with the reset password in recovery mode
I am running Mac OS High Sierra