Default [Q] Cm 11, Moto G, no Media shown or played by Apollo and VLC

Hello Sirs.
trying since a while.
Apollo does not show any media files. It states (in German) something like "use an USB cable to download media files from your computer"
VLC shows the files with index picture, however crashes when I try to play them. Sometimes it ends with no message, sometimes it just shows (again in German) "VLC stopped".

The media files are flv and mp4 format. I copied them from my linux machine via USB in MTP modus.
The target folder was Music or Movies

The Galery App (Google Video Player) can at least play those mp4 files, so i believe, this is not an issue of file format and/or codec.

My phone runs the falcon M6 snapshot and has no google apps installed.
This problem occured for me in the earlier Snapshots as well.

is there a dedicated log directory on android and CM like /var/log/ that I could check for relatetd errors?

Any hint?
best regards