Thread:Extension talk:UserAdmin/Purge User not working

Going to purge user, I enter a username ("1t6a0t19942") and hit search.

This takes me to the following URL;

http://www.liblfds.org/mediawiki/index.php?username=1t6a0t19942

Which simply shows the root wiki page.

Total fail. Third extension I've tried to obtain the capability to mass delete spam users, not a one of them works.