I'm using a PC running Windows 10 Pro (will be updating to 11 at some point soon). Using Audition version 25.3.0.71 (a fresh update).
When I load up a session file, or open a new session file, playback (either via spacebar or mouseclick on "play" button) will not play. It responds my un-highlighting the tracks - indicating that the input has been received - but I cannot figure out why the multitrack is not playing back.