In the data editor you can modify it under texture sets and pick the tile set you are using and set "background model(fixed)" to one of the sky boxes. Some of them don't work.
If you are having trouble seeing the sky, use a camera and modify it's far clipping-- for some reason far clipping cuts off sky boxes.
I think someone said something about it being different for different terrains. That it's not possible to add a skybox on a map that didnt have one to begin with.
But maybe Im mistaken because Ive heard that some while ago...
Actually I believe your right on only certain maps. If I remember correctly the very first defualt map that it's on when you click create a map works. I don't recall the name but it's just the defualt one.
I don't think I'm dealing with quite the same pressures though, at the very least its a significantly smaller system. For the time being I'm just going to put together a quick scrubby box though and hope it works good enough to not make my house toxic
I do know this - xenforo dropped the ball by not keeping the vbulletin reputation comments as a feature. The loss of the Reputation comments data when we switched to Xenforo really was the death knell for the site when it came to all the users that left. I know I missed it so much and I got way less interested in the site when that feature was gone and I run the site.