Advanced Poll Bug?

I installed the script several months ago and it worked great all this time.
But two days ago, suddenly 5 of my 7 polls were suddenly deleted from the mySQL database.

When I tried to go to the admin page I get this error:

Fatal error: input in flex scanner failed in /poll/db/lang on line 1

Any clue? I tried to upload some backup files of the poll but still get this error. Thanks ahead for the response.