@leocg I have the same problem he has, (no flash) and I do have the 62.0.3202 codec installed. It was the only way to get any videos to work at all. I also installed the pepperflash_plugin_nonfree. I also have the latest libpepflashplayer.so from adobe copied into both the $HOME/.local/opera/plugins, and /usr/lib/oprea/plugins.
(tried it in the $Home/... first) And still nothing. PITA. This is such a common problem with Opera... I can't recommend the browser to anyone, quite frankly. Well, I'd tell them it's great, if you like to be frustrated and spend a couple of hours trying to figure out how to get videos to work... (again.)
I added this extension https://addons.opera.com/en/extensions/details/add-bookmark/
so if I want to add bookmark at the end of bookmarks I use it, and if I want otherwise I use the default bookmark button.