why safari cannot play youtube

YouTube requires the Flash plugin and there are times when it needs reinstalling.

Quit Safari.

Open System Preferences > Flash Player then select the Storage tab. Click: Delete All

Now uninstall the Flash plugin then reinstall new > Troubleshoot Flash Player | Mac OS

Very important to uninstall the currently installed plugin first before reinstalling.

Launch Safari. From your Safari menu bar top of your screen, click Safari > Empty Cache

Now try a video.

If you have the ClickToFlash extension installed, that can prevent Flash based video from streaming. It can also be installed as a plugin in /Library/Internet-Plug-Ins.

And check to see if Safari is running in 32 bit mode. Right or control click the Safari icon in your Applications folder then click Get Info. If the box next to: Open in 32 bit mode is selected, deselect, quit then relaunch Safari.

edited by: cs

Download Abode Flash Player or update the flash player to a higher version, check to see if youtube video watching is blocked.

Go to

http://www.verticalforest.com/2010/06/09/youtube5-html5-converter-for-youtube-vi deos/

follow the instructions and install the extension. It worked fine for me.