Unable to open playback device. etc

I've researched this issue in the forum and found anything that fixed the problem. I have been experiencing it, with opening any project more than three weeks old. New projects open fine. The older projects were opened and played just fine when I played them for a friend in June. I've changed nothing in Sonar (Platinum) since then, EXCEPT for Command Center updates. The sampling rate in Sonar matches the sampling rate of my Presonus Firebox. 24 bit is auto selected and grayed out so I know that hasn't changed. I'm using ASIO drivers and WDM is not an option with the Firebox.  I would appreciate any help you guys can give me.

I was going to call tech support today but forgot about the 3:00 pm closing time (I'm on the West coast)
So I'm really hoping someone can help here. Thanks

Hi Anni,
What actually happens when you open the older project? (do you get an error message or Sonar closes or ???)

annifarkle
Thanks Mesh - the message was "Unable to open playback device, etc" on anything older than a few weeks old. Sonar remained open and I could pull up newer things that played OK.

I was on the phone with tech support and we finally arrived at a solution- (After deleting every track in a project and still getting the same message) we tried uninstalling the Presonus drivers and re-installing. Everything back to normal. It didn't occur to me ot the tech guy to do that right off the bat because newer projects played just fine.

Glad to see you got it resolved Anni.......as always, it does take a bit of work to get all the equipment to see eye to eye.