I tried un-installing (sudo apt remove synergy), deleting config directories (as recommended in the other thread), and then re-installed with a fresh download (  sudo dpkg -i synergy_2.0.10.stable~b20+ecfd5e95_amd64.deb)  Started synergy, it registered me again, and I'm back to the same error.   And yes, I did already submit a ticket, but was hoping there might be a quick short-term fix the community might have.