About [[MediaWiki:Smw qc query help/en]]

Also, shouldn't {{ns:category}} have a : before it? The message, as well as this thread, is currently included in Category:Actor.

Solely with regard to the message itself it should definitely not have a „:“ in front of the namespace. I think the particles in the message sould be nowikied to solve this problem. However, so far I did not have the chance to see this message in action. I have asked a developer for this extension to have a look at this discussion.