Getting
-12 as an error generally indicates that your control file is corrupted.
Can you check first whether this is related to
another recent bug report? Speachy has posted a few builds near the bottom of that page. Please try the following two builds and see if you can reproduce the issue in one of them:
https://www.shaftnet.org/~pizza/rockbox-ipod6g-1241016-9b1a92fe36.zip
https://www.shaftnet.org/~pizza/rockbox-ipod6g-1241018-ac46684d7f.zip
In case they work fine, please go back to the daily build. If you don't mind, upload the file that is named
.playlist_control from your
.rockbox folder (after recreating the issue). You may have to append a .txt extension to the file name to get it to upload here.