Problems playing MP4

I have problems playing MP4 movies using the Android Client.
Could not find a solution on the community.

We are using Minix Mini NEO X7.
Have the .59 Client running on it.

The MP4 is downloaded to the device and present in the Xibo Directory.
I can play it using any other player on the X7. But in the Xibo App I only see a black screen.

Any suggestions?


Can we please see a screenshot of status window on your device?
It should make it clear what could be wrong.