This error message

I have Mac OSX v. 10.7.5. I am trying to use a Tape to Digital Converter to convert some old cassettes to mp3. I can export files just fine, but I cannot get the correct thing to record. I have the cassette in and it is playing, I can hear it through my headphones. However nothing records on Audacity. I set the input on my computer to USB microphone, as well as recording device in Audacity. Wasn’t sure if the channel should be mono or stereo, but neither seems to work. Now that I changed the input, I get this error when I hit record: Error while opening sound device. Please check the input device settings and the project sample rate. What does this mean??? Thank you!

I have been known to need to set these things in Audacity and Apple > System Preferences > Hardware > Sound > Input.

Sometimes you can make that error go away by changing Audacity Quality from 32-floating to 16-bit – all this assuming the device is working correctly. If it doesn’t show up in System Preferences and make the blue ball sound meter bounce, Audacity will never find it.