After recording sound from website, no sound during playback

When I tried to record sound from a website (which I have done numerous times successfully) I received an error that said “Error opening sound device. Try changing the audio host, playback device and the project sample rate.” The error does not direct how to do this.

I upgraded Audacity to version 3.0.2. I thought that would solve the issue. It did not. I referred to my old notes (I’ve had this problem before). I changed my Audio host to Windows WASAPI - Speakers / Headphones (Realtek Audio) (Loopback) - 1 (Mono) Recording Channel - Speakers / Headphones (Realtek Audio). (Please see attached). I have been playing around with these settings. I finally got the audio to record. Now there is no sound when I playback. Or, I click Play and get the error referenced above.

I am running Windows 10, 64 bit.

So, either I get the error noted above or the song plays with no sound. Please help.
Audio Device Toolbar.jpg
Thank you,

The audio host and playback device are selected in your Device Toolbar, of which you have posted a screen-shot. The project sample rate is in the lower left-hand corner of the Audacity screen.

You seem to have a simple straight-forward setup. I don’t see why you are having this problem. Perhaps some settings got jumbled somehow (They are not BTW, reset by an upgrade). Instead, do Tools > Reset Configuration. Hopefully, this will correct the problem. If not, does recording in stereo make any difference?

What happens when you you Generate > DTMF Tones into an empty workspace then click play?

If this doesn’t work then check the sample rate in the Track Control Panel. Is this 41000Hz?

Now in the Windows Search Bar (by the magnifying glass), type “mmsys.cpl”, and check the Playback tab. Select your playback device (speakers/headphones), click Properties, then Advanced, and check your Default Format. This should be the same number as in your Track Control Panel. If not, there will be problems. BTW, check your Recording Tab as well.