One of my testers just got this error while playing:
Can anyone tell me what this means, and how I might fix it? 
I tried “Use MStack of 999.” and it compiles, but I honestly don’t know if it helped as I can’t recreate the error.
This is probably an infinite loop (or recursion). The first question is, how did the player do that, and can you reproduce the error?
(Saying “Use MStack of 999” does nothing useful. I7 doesn’t recognize the option and tries to pass it along to the I6 compiler, which ignores it. You could increase the MStack size by hacking on the MStack.i6t template file, but if you’ve got an infinite loop, no number is big enough.)
Thanks, found it and sorted it out. 