I just installed the Opera browser following this procedure:
https://rpm.opera.com/manual.html (seen viewtopic.php?f=7&t=12423#p73009)
Everything works fine except the playback of the videos. When I try to play a video on Twitter, I get the message "Media content could not be played".
Similarly, when I try to play a video on Facebook, I get the message "We are having trouble playing this video."
I add that I can perfectly reproduce those two videos when I access from Mageia-Chrome or from Mageia-Firefox.
How can I solve this?