Playlists not playing

Hi all.
I have just found that if I go to my playlists, they are all listed but none of the tracks in them will add to queue or play. I just set up a new playlist, added a few tracks and all is well on that one. I have done a re-scan but no change.
I am using V2 and my music is on a USB hard drive. Any ideas?

Thanks

Check if the paths in the playlist are correct.
via SSH:
nano /data/playlist/<playlist name>

Ok I assume I do that by enabling SSH then using putty?
Sorry but I am a complete novice.

Update.
Volumio has gone up the creak completely now. I flashed another SD card with my back-up image and all is well.
I really don’t know why corruption happens. Oh well!

we’ll the most common issue is with the PSU, those with just enough power to boot but failing when additional items are used ot plugged in

Thanks for the tip, but my power supply is fine. I have been running my set-up for nearly three years now and the only problems I get are if a power outage kills my SD card when it is on and running. Normally I shut down using the safe shutdown button I have configured.
I have got two power supply units. One powers the USB hard drive and the other (19volts) powers the Pi via my DAC/AMP hat.
If there was a simple way of installing the Volumio software on the USB hard drive, I would do that instead of killing the odd SD card.