Hi! I have got a big problem that took hours of my patient attention, but nothing helped(or I have done something incorrectly). I am unable to play most videos on the internet. For example, i can watch video in youtube, but when i play stream on the same platform, youtube complains that currently my firefox browser does not recognize any html5 video formats. Plugins installed: OpenH264, Shockwave Flash, and... while writing this question i've found that there's also widevine cdm that i tried earlier to install in my browser, 'cause by default in my Ubuntu 20.04.1 LTS there's no such extension. I tried this to install widevine. Maybe I have done something in the way it shouldn't. 1)https://support.mozilla.org/en-US/questions/1207502 2)Reinstall firefox 3)Trying disabling any combination of installed extensions to find the "wrong".