Covers are gone...

Hi,

ich have lost a lot of CD Covers in Recordbox! How can I fix it? In iTunes they were shown. When I delet my collection an reload it, they are there again, but not, when I'm restoring it. But I need to restore, bcause otherwise all my Cue points, loops, all information are gone.

What can I do?

The information without the Covers are on a USB Stick as well!

THX