I am using openSUSE Leap 42.2 and Opera 46.0.2597.57.
Some videos on the internet (maybe the half on YouTube) do not work on Opera. YouTube tells me that I cannot watch the video and suggests me visiting https://www.youtube.com/html5. H.264 and MSE & H.264 are not supported by my browser as the page mentions, although Opera is listed as suported.
I did some research and installed the following packages (which were not the sollution):
Maybe I need to mention that Firefox works pretty fine with YouTube and other videos that do not work on Opera.
Thanks a lot for your help.
PS: If this issue is fixed with openSUSE Leap 42.3 this would be an option for me, but I still hadn't enough time for an update.