Hi Kevin, I found your thread by searching on the error message - which I am also getting. There are 4 lines of text that are written to the ACP log window:

[Source: System]
[Unable to write data to the transport connection: An existing connection was forcibly closed by the remote host.]
[This is not an ACP problem]

I had done an AutoFlat (panelflat) run about 10 minutes before, and was using Maxim to take a manual flat frame. Then I noticed that ACP had disconnected from my scope and the above lines had appeared in the window. I also use a 10Micron mount so I wondered if it's the same error you encountered.
Do you have any more info on this issue?