Thanks for your feedback, Stijn!
I would connect the Genos as the next step via USB cable to the computer and then boot the Genos in the USB Storage Mode (hold down the "Playlist" button while powering on). After a short time, as you probably know, the Genos User drive should be displayed as a new removable drive on the computer. Please check whether the system folder "PLAYLIST" exists here (in addition to the other system folders "Expansion", "MULTI PAD", "REGIST", etc.).
If the "Playlist" folder exists in the User drive, I would copy a .tsv Playlist file into this folder on the computer. Then reboot the Genos and check whether this Playlist can be called up via the User button.
If the "Playlist" folder does NOT exist in the User drive, it may have been accidentally deleted or moved by the user at an earlier USB Storage Mode session. This would explain the problems you described. I would then check (in the USB Storage Mode) whether the "PLAYLIST" folder can be found in another folder in the User drive and then move it back to the right place, i.e. to the root directory of the User drive. If the folder cannot be found, I would create a new "PLAYLIST" folder there and test again on the Genos.
If it still doesn't work as desired, I would first backup the actual content of the User drive using the USB Storage. Important: If Audio Multi Recording has already been used, make sure that hidden files and folders are displayed on the computer in order to also backup the folder that contains these Audio Multi Recording data. (This hidden folder is called "AUDIOREC.ROOT" if I remember correctly).
Then I would RE-FORMAT the internal User drive ("Menu > Utility > Storage"). Attention: all the data is of course deleted, but the required system folders are automatically created then, and actually everything should now work as desired.
Best regards,
Chris