videos get thei response from browser No compatible source was found for this media.
Fire Fox will run some videos- I get this response No compatible source was found for this media.
Depending on how you installed Ubuntu (I assume that's the Linux distro you are using), it may not have installed the 3rd party codecs needed to play HTML5 video content.
On Ubuntu, you should try installing FFmpeg using the following command in the terminal:
sudo apt install ffmpeg
Hope this helps.