XF 2.1 Forum down Mysql error


I'm a bit lost here. Not sure where to go fix this or how or why this happened. Any help would be greatly appreciated. Just wanna know where to fix this. Thanks:

An exception occurred: [XF\Db\Exception] MySQL query error [126]: Index for table './forumpul_forumsxenforo/xf_session.MYI' is corrupt; try to repair it in src/XF/Db/AbstractStatement.php on line 217