error code -9997 when recording vox track alongside music track [SOLVED]

A conundrum. I have a Rode Procaster mic running through a Xenyx Q8902USB into Audacity 2.3.3 on Windows 10, which I am using to record the vocal track for a radio show.

If that track is the only one then I have no problem. However, introduce music tracks (MP3), and when I try to record, I get the error message:
‘error opening recording device. error code: -9997 Invalid sample rate’.

As a workaround I can open a new Audacity recording, record the vocal and then cut and paste the recording onto the original vocal track, however it is really irritating aligning the vocal to the music tracks.

I have looked through the forum, and all the settings seem to be as recommended. Any help would be gratefully received.

Ensure that the Windows sample rate settings for the recording device and playback are both set to 44100 (In the Windows sound settings)

Problem solved - thank you so much.