which version   your opera is ?

i found the office website , the version is stable and it should be opera's problem

Maybe you can try another  Browser. for example the vivaldi https://vivaldi.com/

The opera cannot play the html5 video.

It's missing codecs. Here's a fix: https://www.plop.at/en/ploplinux/desktop/vivaldi.html

This fix applies to any Chromium-based browser that's missing codecs on Linux, by the way.

Latest Build

Edited by primta at 2018-8-28 21:28

I use Opera with no additional plug-ins and it plays HTML5 videos just fine.  I'm not sure what's going on there? Some sites do require flash though.

Checkout Youtube Live Video

You're correct , I'll have to look in settings and see if there is anything related . Firefox works fine  on that page.   

The page works fine on my Ubuntu installation   , so there is obviously a codec package/s missing . I ran across this post.

https://elementaryos.stackexchange.com/questions/15321/youtube-live-video-not-working-in-opera-and-chromium

Fixed !

Install libavcodec-ffmpeg-extra56 from the repository and Chromium-codecs-ffmpeg-extra.

https://pkgs.org/download/chromium-codecs-ffmpeg-extra


On the speed dial page enter chrome://flags

Scroll to WebAssembly streaming compile/instantiate support and select enable. Scroll the restart option to confirm.