Have you put any other objects in the mission at all? A battle maybe? Some of the things you can add sometimes take up spaces you don't expect. If that's not it most likely you've just found some maps with the wrong info attached, so bug them.
I haven't had this problem yet but the error reporting tool is a little flaky. It usually seems to miss problems rather than reporting false ones though.
"If there's anything worse than being sacrificed, it's being sacrificed incompetantly."
Sorry I had messed up for this one, setting the number of those to rescue to a too high value. Beginners mistake...
Well, under the map description you can see how many different goals are allowed on that particular map. Does that really work?
I'm working on a mission where I have choosen a custom map (Unique maps - Office - Hellions) that allows;
* 8 ambush, boss, patrol or destroy object
* 7 rescue, escort or defend object
So I've added 7 'release captive' and now I get "There are too many Rescue, Escort ... etc... for the current map. " I tried a standard map without any limitation and I still get this error message. Is there someone who can see the problem? I obviously can't!
Edited:
OK... so it works for some maps but not for some where (as I interpret the info text) it should work. I also hade the above error but still been able to start testing the mission, whereas in some cases I can't. Bug or my misunderstanding? You tell me.