I messed up my config and now my wiki is inaccessible. What can I do?

You can always change the configuration manually by editing ./conf/local.php on your server.

If you don't remember the name of the config option you changed, try figuring it out from the list of available config options.

If you still don't know what to change, just delete most of the content of ./conf/local.php (after making a backup!). (You should keep the useacl and superuser options.) That way you will at least have a vanilla configuration and will be able to adjust your settings again.

For more information see config.