All my 19500 aac files on iTunes have artwork, these files with artwork have been copied to micro card and used I Cowon Plenue player and every single one had its artwork there in the player. Using the same card in the M11 all the songs are there but not all the artwork is showing. When I view the card on Mac with file explorer every music album folder has still got the artwork. It seems that the M11 just does not like some of the artwork and has "censored" it and will not show it when playing. Still mystified, it does the same with some flac albums as well and I know these all have artwork too. It must be the Fiio music program??
Odd. I copied everything from my iTunes folder structure to my two 400GB cards and all album art is shown without issue in both FiiO player and Poweramp on the M11. Not sure what the issue is if you have embedded all art work in each individual track.