I found this program and like it very much. Deep into a project it began to give me Code 0 error. I have read the “fixes,” but none of them make sense to an end user who is not an engineer (and I’m not). In simple language, can someone tell me how to fix this problem so I can get back to work.
I have read the “fixes,”
Can you post some of them or portions to give us a hint? I’ve never met a Code 0.
What’s the show? How long is it? Are you doing it on External, USB, Network, or Cloud Drives?
Koz
You can try Transport > Rescan Audio Devices.
Also, you might want to check that the Audacity Project Rate in the lower left-hand corner of the screen agrees with with both the Recording and Playback sample rates for your device. On the Windows task bar, click the magnifying glass and type in mmsys.cpl. Then, on each of the Playback and Recording tabs, select your device > Properties > Advanced > Default rate. Generally you will set these to 44100 for audio work and 48000 for video.
Also note when using Overdub, the number of recording channels needs to match.
I’ve never hear of “Code 0” either.
What’s the full error message?
Perhaps a screenshot would help us to understand the problem.
I’m surprised. 
try searching for “audacity forum error code 0 success”
That exact search term in Duck Duck Go returns one result - this forum topic. 
I see now that it is probably:
Error Opening Recording Device.
Error Code: 0 Success
in which case, as Jademan suggests, try “Transport > Rescan Audio Devices”
Also try google
Or a forum search with “error code 0 success” - a little messier - but to the point