Cannot record

I had the same problem. I could hear the input device via the playback output, but Audacity always displayed the error message when trying to record. I had tried the other suggestions in Audacity Help to no avail. For me, the solution was to change the account privacy settings to allow application access to the microphone. To do this, from the Win 10 Start menu, select Settings (the gear), then Privacy. On the left side panel under “App permissions” select Microphone. Check that “Allow apps to access your microphone” is set to “On” (you can then enable/disable other app access below this setting).