Umm... might this enhancement possibly have included an "Invalid ship class name: Live Shivan" ?
Because I was crashing exactly before the briefing for that mission with this error when I used yesterday's file,
with today's version, everything works fine so far.
I'm attaching a screen shot with the error from yesterday.
Quite a coincidence to catch a bug that lasted for a day in a years-old mod
on first install.