Hi,
The namespace restriction for the namespace Category is broken.
According to user group rights special page, to edit pages in Category namespace you need the right sysop, which nobody has.
Could you please rename (in $wgNamespaceProtection, and perhaps in $wgAvailableRights or in $coreRight in PermissionsManager.php) the right sysop to something more revelant (for example editcategorypages) and then add this right to the group sysop (which perhaps was what the sysadmin meant to do)?
This will be useful to be able to edit the pages of categories used by template (to create/rename/delete them and specify what they are).