"..check the output device settings & sample rate

I’m running Mac 10.6.8 on a MacBook Pro. When I try to play back my recording I get - " Please check the output device settings and the project sample rate". I’ve have gone to the Utilities folder and everything appears to be right but I’m not sure about the “sample rate”. I see the waveform when I record but get that message in play back. I’ve searched the Net but don’t see anyone having that problem with 2.1

I don’t use Macs but perhaps this will help:

The current version of Audacity is 2.0.2 which you can get from here: http://audacityteam.org/download/

Re. the error message, see here: http://manual.audacityteam.org/o/man/faq_errors.html#sound_device