Without any update or configuration change on MacOS Sierra ver. 10.12.3 my free licence TeamViewer 12 ver. 12.0.75813 stop to respond to connect command. I tried to reinstall it but without any result. On Mac Tv has all "clear to go" and I see my other computer (Windows) as well as "Ready to connect" signal. But when I click or try to use any other command option to initiate connection, nothing happened. As I did not click on anything. When I try to connect from other computer to Mac using TV connection is refused with "Reason unknown".