The album cover art may be too big for the program. 512x512 is the normal cover art size for media servers (no greater, can be less), if you go above that it may not show. The album art is sometimes integrated into the files if commercially bought but if you digitise your own CDs it may not be. I rigidly put the album art cover into a file called cover.jpg - most if not all media server software handles that so you can copy music files between your home media player and the car.
That album art file goes in with the tracks. Least on mib2 it reads that. The art file can be taken from a Google looking at the images tab for ones of the suitable size (e.g.. Amazon ones, discog etc) or if you have a large album art cover you can resize that yourself.
Reckon if you insert a cover.jpg file with those parameters in the offending directory it will show on the screen.
As far as the maximum number of files you can have on your media, mib2 had these limits:
– Playlists in the formats M3U, PLS, ASX and WPL.
– Playlists must not exceed 20 kB or more than 1000 entries.
– Filenames and paths that do not exceed 256 characters.
– For DVD, a maximum of 1000 files per storage device and directory.
– For memory cards, a maximum of 4000 files and a maximum of 1000 files per directory.
– For Jukebox (SSD) a maximum of 3000 files.
We can discard the DVD and Jukebox. The manual for the FL models to me doesn't reveal what the limits are, if any, I may have missed it thou. The limits were simple programming limits in how the software was written so they may have have upped these. Possible not the 256 characters, but the playlist 4000 files, with a maximum of a 1000 files per directory may have been increased.
If you presented mib2 units with an SD card / USB that broke those latter limits it would see up to, but not beyond. People would ask on boards why they were not seeing all of their music. Answer was it only indexed the files to those limits but didn't show the rest. (bit like package programs you would write yourself in the 70s/80s where you didn't declare arrays big enough or use pointers within the memory
... There lays their programming
problem).
If you are using a 64 gb usb in place of 32 gb you may hit the limit if these limits still apply to mib3. Only really mp3 files where mib2 limits could be hit. Flac files are sufficiently large even with 128gb storage not to be an issue with mib2. I did some back of the envelope calculations at the time before I ordered the 128gb cards.
Needs somebody to check whether these limits apply to mib3 by presenting some files that break the mib2 limits above.
