Problem with video playback of AVI (Xvid) on Sony BDP-S186 [solved] I'd like to play an AVI on my Sony BDP-S186. 
The user manual states: Supported Codecs and File Types: including Xvid (.avi) (http://pdf.crse.com/manuals/4290282312.pdf - in German).
I'm trying to play the file from an USB stick. 
The video file's codec is MPEG-4 Video (XVID). 
The device says "Die Datei ist verfälscht oder unbestätigt," which means that the file is corrupted.

Sometimes it works for AVI files, sometimes it doesn't and I actually do not know what's the reason for the issue. The issue seems to be well known by the internet, but I didn't find an appropriate solution for now.
This forum deals also the issue: http://www.cczwei-forum.de/cc2/thread.php?threadid=6317 (in German) 

I'm buying the capability of playing files with that format/compression and not the capability of not playing them. 

I would also be interested in the legal side of this issue. I don't think the cause for not playing specific videos is caused by copyright protection or anything related, even if Sony qualified themselves always for being a bad example of copyright protection guards.
I changed the file system on the USB stick from FAT32 to NTFS. The video playback works now.