You can try if deleting your savegames helps. In order to do that, delete the prefs.prop and the .save files from this folder:
~/Library/Application Support/Telltale Games/TheWalkingDead/
You might want to make a backup copy of the files before, in case it's something different.
I am a Community Moderator, and I am here to keep the Forum a fun place for everyone.
My posts represent my personal opinion. I am a volunteer, not a TTG employee.