Playback Error

Audacity has, all of a sudden, ceased to play back. When I click the play button an Error window pops up that reads: “Error while opening sound device. Please check the output device settings and the project sample rate.”
Can anyone tell me how to fix this?
Thanks for any help.

What are you playing back into and did you change it? Are you playing to your internal speakers? New USB Headphones? Describe your system. Koz

I haven’t changed anything. It’s played back through the external speakers I have plugged in since I set it up when the new iMac arrived two weeks ago. If anything got changed, it was an accident. I haven’t intentionally changed anything.

All of a sudden, Audacity has begun to playback again. So I suppose the problem solved itself, at least for now.