The past vew versions of TeamViewer 12.0.78517 on 2 of My Macs have not been showing the main connection window. Selecting Bring all to fron does not show anything. So Basically I cant use it. 
Until Recently I found that if I select the Ceck for Updates option, it checks, says I'm up to date and then shows the main window. 
How can I fix this, its pretty anoying to have to check for updates to get to the main screen.
 
Thanks!