Nope he is talking about testing his map he made locally.
What that error is telling you is you have placed things in there that do not belong. Example
If I made a map that was for JO IC and someone with only JO loaded could not play because they do not have all of the items the expansion IC gives out.
So there is something in your map that is not supposed to be there.
They only thing to do it remove items one by one.
If you tested it before fine then it has been something you placed since the last test.
Hope that helps :comp