Safari 5.1 won't play video on YouTube

I have a problem with you tube videos on a Rotary site. They both work fine on Firefox and ran Ok on Safari until recently. Noticed the problem after I upgraded my iMac to Lion . Checked the MacBook and it was OK on Safari. I thought that it was Lion> Last night ran software updates including Safari 5.1 and problem now occurs on Macbook.

The videos are Rotary ones (not private) and have been embeded. One appears outside the confines of the Safari page and will run the other does not work at all. Have tried switching off extensions but no joy. Reorted problem to Apple. Any one else with same problem.

No flash items will work since I upgraded to 5.1 and everytime I switch windows, the page is blank and I have to wait for it to "redraw" before I can view it... very annoying. I am now using Chome until Apple gets with the program and fixes this fiasco. This update was definitely not ready to be posted.

What version of Flash did you have installed (that would be the plug-in in question)?

Whatever flash plug-in update software update pushed through. I haven't had to update Flash for my mac since Safari began. It was always done by Apple

Uninstall the current copy of the Flash plugin then reintall new.

Troubleshoot Flash Player | Mac OS

Make sure and empty the Safari cache before you stream YouTube content after you reinstall the plugin.

Safari / Empty Cache.

TheSquirt, Apple stopped bundling Flash with updates. Thus, your version of Flash is likely out of date.

http://daringfireball.net/2010/10/apple_no_longer_bundling_flash_with_mac_os_x

I wish Adobe and Apple would kiss and make up already. Maybe then the iPad would function as well as the other tablets and be worth purchasing.

I just had the same problem and fixed it almost immediately and more simply. Unless someone has already posted this (sorry) here's what I did.

1. Down load Applejack

2. Follow instructions and restart holding command S (single user mode) makes you feel kind of really knowledgeable when that code like screen comes up. Scarey , but don't worry.

3. Follow the applejack instructions towards the bottom of the screen and you should be good to go.

Hope it works as well for you as it did me.

Good luck.

YOUTUBE VIDEO PROBLEM SOLVED!!

For some reason only a select number of people have this problem. Including me. SO I right clicked on the YouTUbe video, but found NO FLASH options. Instead, something different, including the problem.

Go ahead and right click on your youtube videos that wont play. If you see a menu with the bottom one saying ABOUT HTML5, click on it, and go down to the bottom, and OPT OUT Of HTML5.

Your you tube videos will now work., as did mine.

Obviously, Apple is trying to get everyone out of flash and into html5, but guess what Apple? Try to make your html5 WORK FIRST before you do it. instead we all got spinning you tube players that never started.

MAKE UP WITH ADOBE PLEASE! You can then squash all iphone and ipad competition. Maybe now that jobs is gone Apple wont be so hard headed.

@unclepete THANK YOU!! I tried uninstalling 5.1, back to 5.0.5 only to have the same issues. Then back to 5.1 and the issues got even worse, this is after making sure all Internet Plugin's were eliminated and newest flash plugs installed. I was at the end of my rope! Not only was I having problems with Safari not playing videos on YouTube (only would play audio) and other video sites, but some of my pro applications started getting weird on me, saying I had no VRAM (thats a whole other topic!). I made sure I had applejack for SL installed, then did the "Command-S" at startup, went through all 5 steps, and POW!! When I rebooted everything worked, including 5.1 complete with YT video and audio with no weird page refresh issues!!

APPLEJACK IS THE ANSWER. Everyone needs to try that FIRST, before messing about with the plugs, installs, prefs, etc.

Model Name: Mac Pro

OS: SL 10.6.8

Model Identifier: MacPro3,1

Processor Name: Quad-Core Intel Xeon

Processor Speed: 2.8 GHz

Number Of Processors: 2

Total Number Of Cores: 8

Memory: 8 GB

Nico521Bucs! You're the best! Thanks!!!! ^^

Same issue. Tried everything. This worked immideately.

Open Preferences. Click "Security". Click "Remove all Website Data"

Second this solution. Easy and quick fix. Worked for me as well.

I don't know about you but opting out of html5, like Niko said, makes more sense to me... Not sure I like the AppleJacks thing or having to remove website data everytime. Is there a downside to opting out? Who knows, at least it borrows us some time while Apple investigates.