Thread:Project:Support desk/MW 1.23 Category pages not being linked if spaces in name but works with/reply (8)

I'd try to set up a new wiki, on an empty database, and see if the problem is reproducible. If not, try to enable the same extensions you have, and test it again. If everything works, perform the upgrade again, being sure you extract the files of the new installation on a new, empty directory and not overwriting the old installation, copying your customizations (LocalSettings.php, images...)