How to get Back To The Future - The Game to work on Mac OSX

Everytime I download a new episode of "Back To The Future" from Telltale Games I end up with a screen that looks like the one below.

I can't start the game from this screen. For episode 1 I could get the game started if I disabled the network connection. That didn't work for episode 2 and know I see the same issue with episode 3.
On the forum from telltale games it takes a while before a solution comes up.
I now found a solution (specifically for the mac) that seems to be the right way to solve it:
Try 'Command'+'Shift+'-' (yes the actual -), press yes, then 'Command'+'Shift+'+'. Then log back in.
An alternative option is to run the game as root. From a terminal run:
sudo /Applications/BackToTheFuture103.app/Contents/MacOS/Mac_Game