Yosemite + Safari + YouTube = Not Working

Apple users with latest software can relate.

I have the latest versions, OS X Yosemite 10.10.4 and Safari 8.0.7. and this is the result when you visit YouTube.

Obviously, I don't want to download Flash to my Mac because of reasons. I click on "Get the latest version of QuickTime" and the link (https://www.apple.com/quicktime/download/) brings a page that states "QuickTime is built into Mac OS X",and software update states that I have the latest version of QuickTime (10.4). It's a loop.

The only workaround I have is: Developer Tab > User Agent > Pick one of this:

Safari iOS 8.1 - iPhone

Safari iOS 8.1 - iPod Touch

Safari iOS 8.1 - iPad

The iPhone and iPod Touch options don't let you choose resolutions. The iPad option let you choose from 240p to 720p (no further), because it is a mobile version. I'm not sure why 1080p can't be a selection, because of iPhone 6 plus resolution, I don't know the reason behind it.

After you make the choose the page reload with the selected settings. If doesn't reload and redirect you automatically, you have to switch to mobile, press play and then choose the resolution (the option appears after you press play).

Resume: (TL:DR)

1. Go to: Developer > User Agent > Safari iOS 8.1 - iPad

2. Wait for automatic page reload

2.1 If don't redirect you to iPad mobile YouTube interface/page, click on mobile YouTube option (redirects you to m.youtube.com)

3. Press play to video

4. Change the resolution (max. 720p)

It's just a workaround that allows you to see YouTube videos at 720p as top resolution (despite the video it is available in 4K, 1080p for instance).

As far as I know, Apple just don't know how this happened nor how to fix it. I just hope any Apple worker can enlighten me.

PS: Excuse me if I have gramatical errors, english is not my native language.