The situation is that when playing back a track unless the Software Playthrough(SP) is checked there is no audio. There would be sound coming through the headphones just fine prior to upgrading to 2.1.2. All other players work just fine. Is this a bug? Is there a fix?
If you are recording something I suggest you start by telling us what you are trying to record, using what equipment (makes and model numbers are good), and how that equipment connects to the computer.
In Audacity supplied by us http://www.audacityteam.org/download/windows software playthrough is not required for playing an already recorded track, only for listening to what is being recorded while recording takes place.
Moderator note: embedded links removed !