youtube video formats not recognized
I'm receiving the error that the firefox 62 version that I have does not "recognize any of the video formats available" on youtube and I have also been having trouble with being unable to open other webm formats. I have as the other solutions asked refreshed firefox to it's factory state but that has still not solved the problem. I have checked the plugins page and it does show that the openh.264 plugin is there. Not sure why this could be happening. Ubuntu Linux 18.04
You can test at say https://www.youtube.com/html5/ as all check marks should be blue.
If a couple are red then you may not have the appropriate FFmpeg package installed. This package among some other packages may not get installed in a new Linux distro install due to legal or copyright reasons. Ubuntu for example has a Ubuntu Restricted Extras for this.
Now that you say that, that does sound correct. but I'd be remiss to mark this solved as I cannot test it since that computer is encountering a hardware error at the moment.
And yes I had already been rerouted to that page and the two middle checks were not fulfilled.
For the middle checks -- H.264 -- ffmeg should help.