2.1.2 251 not shwoing embedded covers

[Manelus]

Thanks for your support, I'm about to panic.
I performed a full rescan (2+ hours, 40007 folders 441000 files), no change.
Uninstalled and reinstalled Mosaic, no change
Uninstalled and reinstalled minimserver, no change
Installed an old version (0.8.5.2.1), no change.
Installed 2.1.2 again, no change.
Used Mosaic from another device. no change.

What happens is:
If in a folder there is only a folder.jpg file, but no covers embedded in files it goes fine.
But if the files have also embedded covers, I can see the small covers in the play list, but as soon as the file begins to play, it goes gray, see attached pic:    
It has worked fine for years, may I have reach some limit???
I'm 69, too young to die in desperation

Thans in advance