virtualbox.org

hi.
host: windows 8
guest: windows 7
problem:
when i open a video (flv,mp4,mkv) in the guest-system the vlc-player closes without a message.
(same problem with windows media plaer. (klite-pack is installed))
does someone know how to fix that?

Enable 2D acceleration and install Guest Additions. See user manual for details.

already installed guest additions (with 3d acceleration) and activated both