The registration shouldn't have anything to do with saving a PDF but I tried that and it didn't work... Thanks for the reply though! This is what's frustrating me so much is that there is seemingly no difference with the software from day to day but, Adobe has simply - "derrrp" - forgotten how to write to PDF and in it's own confusion tells Windows that it needs to shut down. It's also frustrating having to resort to these forums for answers because they're not in real time like a phone call or chat. If I could just talk to someone from Adobe about it, since it is their product, I could have tried that option hours (or days, really) ago and have already gone through a number of other options by now instead of being back at square one..... again.
I mean, for christ sake, I even tried a system restore in case I had mistakenly downloaded a font, brush, etc. that corrupted some files - didn't help anything.
I just figured it out. It was the font I was using. Never-the-less, this doesn't explain what the hell happened.
Multi-billion dollar computer software corporations and they can't code to detect something like this when an error occurs. All they can offer is a vague allusion to an incoherence in the system.....