RH8 project aborting during primary layout generation

Hello!
I am using RH HTML 8 and was absolutely loving it until I ran into a problem in one project.
Today, everytime I try to generate my primary layout, it crashes. In the Output View, the last message I see, is "updating files...," then kaboom.
Today I created a bunch of user variables and was substituting them in my text in the topics.

I also noticed that I have two copies of the same project. (Not a good thing, hope that didn't screw me up.) One is in My Robohelp Projects folder and the other is in the directory where all the rest of my projects are. I really can't remember if I copied that project to the My Robohelp Projects folder or not, but it is the only project in that folder and that is the one that is crashing. I compared the files dates in both projects and both have the same info from the last date I worked on the project. So they look identical except for the changes I made today.

I opened the copy that is NOT in My Robohelp Project and generated a primary layout and it worked just fine. The difference is that all my user variable changes that I made today are in the project that is crashing. Poo.

So, my questions are:
Has anyone heard of a problem with user variables?
Is there a way to troubleshoot my crashing project? I don't know where to begin.
Any thoughts on what could be happening here?

Thanks so much! I hate to lose all my work today so if somebody might have a clue, I'd love to hear.....
-Deb