Why am I getting this..?
 

Error description: %s(%s) [%s]: %s /web/forums/includes/class_core.php on line 311

Looks like a mySQL database problem, have you changed any of your databases recently or upgraded any aspects of your server???

have you tried repairing your database, try that and let us know if you get any errors in that.

Also make sure you're using same mysql client library on web server as the mysql version used on mysql server. You using mysql or mysqli as dbtype in config.php ?

:confused:

Or... Go into the file /web/forums/includes/class_core.php, go to Line 311, and see what's wrong? Or post it here so we can help you with it.

I'd assume you edited config.php before the error, remove the white spacing or invalid character you typed in.