two examples:
https://youtu.be/ikqbyjbKAPY
https://youtu.be/415XR5mye3E

The first one says, "This video is unavailable" but the second one works for me.

The problem with YT videos was fixed!!! (at least on the videos that I tested)

Now I can use Opera everyday!

Thank you guys and girls!

Hi all, whether you can see these videos or not depends on the graphics adapter used in your Mac (this is why some people can see the videos and others can't, using the same version of Opera and the same version of macOS).
On Macs that have graphics cards that can't be used for hardware-accelerated video decoding by Opera, Opera's stable version currently doesn't support playing back MSE/DASH videos ( https://en.wikipedia.org/wiki/DynamicAdaptiveStreamingoverHTTP ). These videos are used on Twitter, and in many cases on YouTube (especially for streaming videos).
The current developer edition of Opera (where we test experimental features and new stuff) includes a software video decoder for these cases. If you have this problem, please download Opera Developer from http://www.opera.com/blogs/desktop/ and let us know if this works for you. This feature will become available in Opera's stable version after testing and when we're sure it works as expected.

Wow. I was on my way to give up Opera due to those video problems - Opera Beta 41 seem to solve all my issues. yihaaaooo

I have the same problem of colleagues on some sites is even in the Youtube video is not open at all, when the message was an error try again. I auditioned with Opera Developer 42 and that was solved this problem with videos.

The feature will also be available in Opera 41, currently in beta. This will become the next stable version Very Soon. Sorry for keeping you waiting, just have to exercise your patience a little more now

I hope that the company makes available a faster update possible because it is affecting the use of the browser which by the way is very good taking this problem.

Site: https://tecnoblog.net/202126/perigo-anuncios-maliciosos/
Site: https://cursos7.com.br/restaurando-um-site-wordpress/

https://snag.gy/xW7qfj.jpg

System: macOs Sierra 10.12
Opera: 40.0.2308.8

On Macs that have graphics cards that can't be used for hardware-accelerated video decoding by Opera, Opera's stable version currently doesn't support playing back MSE/DASH videos ( https://en.wikipedia.org/wiki/Dynamic_Adaptive_Streaming_over_HTTP ). These videos are used on Twitter, and in many cases on YouTube (especially for streaming videos).

The current developer edition of Opera (where we test experimental features and new stuff) includes a software video decoder for these cases. If you have this problem, please download Opera Developer from http://www.opera.com/blogs/desktop/ and let us know if this works for you. This feature will become available in Opera's stable version after testing and when we're sure it works as expected.

i had issues with my opera browser on my mac. but i just fixed them simply by opening <opera://gpu> then at the very top "Graphics Feature Status" i used to have "Rasterization" and "Video Decode" in "Software only. Hardware acceleration disabled" mode, which caused many problems with Youtube html5 player as well as several other problems.
The solution is to go to <opera://flags> and in search bar type the specific category of "Graphics Feature Status" (in my case "Rasterization" for example). Since this is to do with GPU, i enabled "GPU rasterization" and right away under "Graphics Feature Status" , in <opera://gpu>, next to "Rasterization" appeared a green "Hardware accelerated" sign.
I did the same with "Video Encode". Literally the same and now i DON'T have to wait couple of hours to see an uploaded video in Youtube in html5, I can watch Youtube streams (also html5). I am not so much into twitter or vine, but i think this fixed ALL my video playback issues in opera. You are Welcome.

I tried your suggestion but still doesn't work.

Here a link to test.
https://gaming.youtube.com/watch?v=q3kS0oILtjc

Every 3 videos that I tried at least one have this problem.

The solution is to go to opera://flags and in search bar type the specific category of "Graphics Feature Status" (in my case "Rasterization" for example). Since this is to do with GPU, i enabled "GPU rasterization" and right away under "Graphics Feature Status" , in opera://gpu, next to "Rasterization" appeared a green "Hardware accelerated" sign.

I did the same with "Video Encode". Literally the same and now i DON'T have to wait couple of hours to see an uploaded video in Youtube in html5, I can watch Youtube streams (also html5). I am not so much into twitter or vine, but i think this fixed ALL my video playback issues in opera. You are Welcome.

Thank you.

The trick is to first download the video to your hard drive and watch it there. If I tried to play those videos listed above inside the browser I got the same errors you all were seeing. But if I downloaded the video first, it played just fine.

If you install the "Video Downloader All In One" extension (http://addoncrop.com/video_downloader_all_in_one/), then go to the YouTube video page, an additional green Download button will appear just below it. Click it, and it will download it to your hard drive and it will play just fine.

Hope this helps!

Dan

The place to report bugs (desktop): https://bugs.opera.com/wizard/desktop

Same here - installed Opera today, as I have done from time to time over the past ten years, only to find that NO YouTube vids will play. Love the VPN Opera now has, but this is a major flaw. Seems there's always something that keeps Opera from being my browser of choice.

I share what you like about Opera. Your experience with videos is similar to what I am experiencing in Twitter. This problem is keeping me from going to Opera full-time.