Thread:Project:Support desk/(Can't contact the database server: Unknown database 'wikidb' (localhost))/reply

Is this hosted somewhere or are you hosting this yourself?

If you are hosting this, then you need to check the mediawiki directory (usually something like /var/lib/mysql) to see if it contains a wikidb sub-directory.

If someone else is managing MySQL for you, you need to talk to them ASAP.