I just received my tablet and wanted to try out the music and video players. But as it turns out they immediately tell me to insert a memory card and don’t even look for media on the internal storage.
Is this an option somewhere, or is this a bug? Or perhaps the music/video player apps just expect a certain folder structure?
Try changing Settings > Storage > Media storage > Default media location to Internal.
It is set to Internal. However, I just realised it came with a firmware version from january, which might explain it.
https://discourse.mozilla-community.org/t/just-received-tablet-a-few-questions/644
I just updated my firmware and I still can’t play video’s from the internal storage 
yep the video player bugs … but you music is fine
That is true. Music does work fine 