Having this crop up in my missions.

Probably a mod issue (I have many). I wondered if someone here has had this and found a fix?
I find it stops the server loading the mission on first try, second try it runs.

Heroes - any joy with this?

I see you have the same issue and narrowed it down to Cup re:
http://alivemod.com/forum/2160-new-error-since-cup-update/0

Sweet