Hi Steve,
OK, I understand the issue a lot better now. Yes, I reckon that you are correct in that the music tracks up to about track 1300 are already in the 'Export' folder, so that's the first query out of the way.
So, I think that the B2 has either a corrupted track/ album at about #1300 or the HDD has become corrupted.
To find out where the Export is stopping you can try the following.
1. Plug your 'Export' USB drive into the B2.
2. From the WebUI, open on the 'Settings & Status' window (click on the little 'Cog wheel' icon in left side window).
3. In the 'Settings & Status' window, click on the 'Wrench' icon; this is the 'Debug' window.
4. Start up the 'Export' function and watch the 'Debug' window.
5. You will see lines of data; artist names, album names, track numbers and names.
6. When the 'Export' stops' highlight the last lines of data in the debug window and cut and paste that information into something like a text file to preserve it. (sequence #, track #, track name, album, artist)
7. In those last lines of debug data, you should see the last artist and album name and track name that the Export processed.
8. I would be inclined to delete that entire album (if it is backed up somewhere else).
9. Rerun the 'Export' and see if it gets past this stage successfully or not.
Then let us know how you got on.
Regards,
Peter.