Using Ubuntu 16.04 with GNOME (which I added later, the original version has Unity), with a Dell Inspiron 15-3531.
After I turn off my computer (with the power button), or make it sleep (shut the lid), at the GNOME login screen which shows the profiles, I click mine, then enter my password. For about 2 seconds it seems like the computer will unlock as usual, but it then loops back to the gray screen with the profiles. It still responds to an extent, as it tells me if my password is incorrect.
I've only been able to temporarily fix it by a full shutdown, or by removing the battery for a minute. Granted, my laptop is old so it could just be that.
Edit: my .Xauthority file is not owned by root but by my user. Creating a new profile does work, however I would not necessarily want to use this new profile as my main. Any suggestions on how to change that? Renaming .Xauthority on my main profile returns "invalid user".