iTunes - An unknown error occurred (-54).

I have an M1 Mac Mini running Sonoma 14.6.1 and yesterday I managed to hook up an external drive to iTunes for my music. All the files are visible and they play fine so I thought I'd cracked it. Unfortunately, when I went to rip a CD I got the following error message:

I have checked the Sharing & Permissions for both the drive that holds the Music folders along with the folders holding the files and they all show Read & Write for myself, 'staff' and 'everyone'. I've rebooted and still get the error message.

Does anyone have a solution please?

Cheers.