The following line was causing Verge to crash on compile with the standard Windows 'geas.exe has encountered a problem and needs to close. We are sorry for the inconvenience' error that happens when something just messes up irrevocably:

efTrigger(itemlibrary[itm].effect_func,user,i,enemy);

The problem, I discovered, was that .effect_func had been renamed to .use_func, so didn't exist! It looks, though, like Verge didn't catch that, and was... messing something up.

I can provide a better example if needed, I'm sure.