Sonic Defender
Headphoneus Supremus
i have cover art embedded in music files which are up to 1000x1000 and still no problems.
So what the heck gives? At the least, and no offense meant to FiiO believe me, seeing as how there are some without issues, and plenty with issues, there has to be a reason, some way to diagnose the issue and tell users that if you have tagged in such a manner, images over size X will be a problem. It just can't be random. Now if it is some really complicated interaction then nobody is at fault, but this image thing is really hard to believe. I don't recall this being an issue on other Android based DAPs, but I could be incorrect. I say this not to be harsh or critical, believe me, I'm actually a FiiO fan, I just can't believe this issue is still so prevalent.
Hopefully those having issues are able to tell how their files were tagged and provide that to FiiO. There must be an underlying cause/pattern to detect.