I have three computers. Two home computers, which are Macs (with the latest OS) and one work computer which is Windows 7. I'm having trouble connecting to one of the Macs from the PC. It shows as offline. It is on and TV is running. Sometimes it will connect after a few minutes or sometimes its hours, sometimes never. This seems to have started after I upgraded to macOS Sierra. BTW the second Mac also has Sierra installed and I never have a problem. I am still using TV 10 as it has always worked for me.
Now that I have upgraded all 3 computers to TV 12, I cannot connect from my Windows PC to either of my Macs at all. They both show as offine, but i see the green 'ready to connect (secure connection)'.