Hello John,

When I say all the other instruments were gone, I'm referring to the fact that I'd loaded Garritan, the string section. I'd also loaded in an Orchestral piece that had drums and other instruments, along with strings... I know nothing (at present) how to go about marrying up Garritan with PG products, which is why I was looking for help... So, I surmise, I'd simply loaded Garritan string section, which took over all the Midi channels I was using, substituting its instruments for the original ones.
When I say I bought Garritan from PG, I did. I also updated, to 2015, all my other products. Band-in-the-Box, Powertracks, Realband etc.
And, as for Acid Pro, I assumed, given the error message, that somehow that was also associated/or interfering with PG products, and may be causing the problems. Although I uninstalled Acid Pro, it's not a problem, I can simply go to Sony/my accounts and download it again. So uninstalling it was an easy decision.

Best regards.
Ken