What is this, and how do you fix it? Posting for a friend.
SQL errors aren't on the users end, they are the server screwing up. If it's still happening, I recommend pm-ing (on skype) or emailing (firstname.lastname@example.org
or whatever it was) your friends account name, the location where the error pops up, steps to reproduce and the exact error.
SQL errors are a very serious problem, if it wasn't during a form of server outage, it could lead to far greater problems later (for all users).