In my case the font changed to something i couldnt read. Any window that had to do with system settings crashed upon opening. I search high and low but couldnt find a solution and i didnt want to clean install again. So I....
Opened terminal logged in as root by typing
log in on the new user account
log in as root again (su -)
then open nautilus by typing
go to filesystem>home>NewUser>
go to "view" then "show hidden files"
now go to the ".config" folder
then open the "dconf" folder
Now copy and paste the document called "user" in the same folder but on the main user account.
Now you can log in on the main account with no problems (other than re-customizing) and just delete the other user you made by typing in the terminal "sudo userdel "username"