Website encountered unexpected error - how to avoid?
Does MySQL crash after that error? Either way your watchdog table is being corrupted. Are you running out of disk space? Make sure you are using InnoDB tables; MyISAM is prone to corruption.

You can check your table type by running this from a MySQL command prompt and looking for the Engine= parameter.

mysql&gt; show create table watchdog;


You can also disable dblog and enable syslog instead. Syslog writes to your system logs and is much more scalable for higher traffic sites. See if that solves your problem.