Thanks for getting back to me but I solved the problem!!  In order, here's how I did it:

1)  I uninstalled Multiplicity on both computers. 

2)  On my primary computer, I deleted every reference to Multiplicity from the registry.

3)  I then did a global search of my PC and deleted every reference to Multiplicity.

4)  Using CCleaner and Glary Utilities, I cleaned my computer & registry.

4)  I reinstalled the software on both computers & VOILA! I was back in business &, ever since, the program has been running seamlessly.

And to think, it only took me 12+ hours to figure it out!!