Thread:Project:Support desk/Database error in upgrading from 1.18 to 1.22/reply (7)

When you actually end up on the page Mw-config/... with capital "M", then you have RewriteRules, which interfere with the update script. For the time of the upgrade you can try renaming the file .htaccess to something else. This will break the output of your wiki, but it should allow you to run the web updater.

I have added hints on what to do when you cannot run php update.php from the shell to the page Upgrade.