I have the same problem on one of my machines. I prefer to keep it on Linux Mint KDE 17.3 and cannot install newer versions of TV due to dependencies. All my other machines (3) run KDE Neon User Edition 1.58 with newer versions of TV. Newer version will not allow connection to older version so I am stuck until I convert older machine to a newer version of Linux. Getting to be a more frequent issue software these days. Things last too long.