I have had to reboot my Nuc a couple of times over the last few months. On both occasions the Storage folder has been empty. All the files have been deleted and I have had to reupload all my music files.
Do you have a second storage drive in your ROCK machine?
Did you format it over the Admin Interface?
Note: The storage folder should contain a sub-directory for your music storage drive. You should put your music files in that sub-directory. If you just copy your music into the empty storage folder its expected that they disappear on a restart (heck, I don’t even know where the files get stored until then).
This is where the music is on my ROCK “R:\Storage\InternalStorage\music”
looks like this in the directory tree:
All the your music files should go in the “music” directory.
“Storage\Internal storage” is the second drive (in my case an SSD) installed in the NUC to hold the media files. The OS is the only thing that can go on the first drive installed.