Yosemite 10.10.1 causing Safari not to play YouTube videos...

I was just going to ask the same question, both I and my fiancee are having this issue. I tried updating flash, restarting in safe mode, zapping the pram all to no luck. I just updated to 10.10.1 last night, but I don't know if this is the issue as he updated the day before I did and just ran across this problem now. Videos play fine on my iPhone on the same network.

Same issue here. Safari just plays a black screen and a 1 second audio clipping. Sometimes I get a screen showing "An Error occurred" but when I refresh I get the black screen. Chrome works fine.

Getting so tired of Yosemite and Safari 8.0 ... Who approved this release?! It's just buggy as ****.

Yep. Same here. Very frustrating. Surely Apple doesn't want us all moving to Chrome? Hm. I zapped pram, I used Disk Utilities. Nothing changes the problem. I also can't use the search option in Twitter while in Safari, but it works in Chrome. I really prefer to stick with Safari, but it looks like I have no choice but to move. :-(

The same here guys, when I updated to Yosemite 10.10.1 , Safari won't run utube videos. I don't know I'm annoyed with these updates that destroy all your system

Getting this too. Same story, updated to 10.10.1 and now no youtube video playback on Safari 8.0

Tried various troubleshooting including clearing cookies/cache/website history, install-reinstall Adobe Flash - no luck.

Read somewhere about Youtube forcing HTML5 rather than Flash Player but not sure if that would make a difference?

Works fine on other browsers (Chrome/Firefox).

Hope there is a fix soon.

Same here, all good until the latest update. Now videos are all black with a big audio glitch at the beginning. Hope  will fix this asap! Come on!

I had problems even to upgrade to 10.10.1 - the super-duper yosemite somehow restricted permissions to itself to download and install any software updates. Managed to repair the issue, upgraded... and just discovered a new feature. Safari does not play youtube video any more. Tried everything I could find on the internet, except downgrading to 10.10 or even Mountain Lion. Firefox and Chrome play youtube video with no flaws.

Well done, Apple!

I didn't get the first issue you reported. I must be lucky but Yosemite caused me no problems.

Now I do have the youtube problem as well though.  will fix it! 🙂

Same issue here. Cannot play any youtube videos. Was working fine last week.

Same problem here... all of a sudden youtube stop working. Working ok on chrome.

Same issue here.

same issue here. I don't use Flash, but the HTML5 videos in Google Chrome play without a problem, so it should work for Safari as well.

Thanks Applewarm for letting me know of this thread :-)

Works if you do this, but that is a temporary fix that resets each time...

Also, Safari crashes when it can't show the video. The window or tab doesn't respond anymore. I had to quit the program twice already.