Table... is marked as crashed and should be repaired
Oh! All of these database errors are like this: Table... is marked as crashed and should be repaired and the additional message (note) "It appears that your database may require an upgrade. Your forum's files are currently at version SMF 2.0.17, while your database is at version 2.0.10. The above error might possibly go away if you execute the latest version of upgrade.php.
So, we'll do our best!