no sound on exported file

when i export the file it looks like it is playing but there is no sound in itunes etc windows 10 os and audacity 2.1.0 I have not had any previous problems

Does that mean you get a silent file? i.e. If you export a 5 minute song, iTunes plays 5 minutes of silence?

I assume iTunes can play other songs?

What format are you exporting to?

Do you see the waveform in Audacity?

When you play file in Audacity before exporting can you hear it?

If you re-import the “bad” file, does it play in Audacity?

If you have connected a USB recording device, see Why have I lost sound after connecting a USB device on Windows?