No sound on recording [CLOSED]

I’ve just recorded audio from a cassette into Audacity. I can play the recording within Audacity without any problems. However, when I select all/export (as both wav and mp3, then I open and play the output in my music player I have no sound.
I’m new to Audacity and am probably making some very basic mistake so I’d appreciate anyone putting me right,
TIA Simon

My Bad. Elementary error. Used a behringer u-control to effect the recording and when I tried to playback on the PC I’d left it connected so the sound was from the earbuds that I’d used to monitor the recording.

So all is fine now.