Messagebox causing assert to fail
To reproduce: "messagebox a a a", in console. I tried to fix it, and removing the assert works, but I figured it's there for a reason, but I don't understand the scripting internals well enough.
(RM-613 from redmine: created on 2013-03-01 by Tom Mason, , closed on 2013-04-12 by Marc Zinnschlag)