I don't build my models sequentially. Therefore the automatic "start channel" assigned was inaccurate.
Going back into the layout, I manually put in the correct starting channel for each of the props. (Direct channel, not the reference that was there.)
During one of the saves (manual - done between every couple of updates) the system would not return. Just hung there. Went like this for over 10 minutes. (All other saves have been instantaneous.) Had to kill xLights using Task Manager.
During the restart of xLights the dump file creation happened. I added a comment and then received the location message from the program. Once I clicked to get by the message, xLights stopped on its own and shutdown.
I have been able to restart xLights, and have been successful in changing more of the start channel assignments.
I do remember something that I didn't earlier. At the bottom of the xLights window, there was a message stating something like "rendering string 1". (Don't quote me. It is late, and I'm past my bed time.)