Youtube no longer working w/Firefox

[Anoat]

Relevant info
Browser: Mozilla Firefox 28.0
OS: windows 7
Flash: Shockwave Flash 13.0 r0

At some point this weekend Youtube stopped working with my Firefox. The video previews and comments sections load just fine, but the actual video is just a black box. Chrome and IE still work just fine. I've got the most up to date version of Firefox and Flash. Checked my extensions and there is nothing funky there. Cleared my cache and still nothing. Help?

[synistar]

Try using the html5 version. I haven't had problems since I switched over. https://www.youtube.com/html5

[Niya]

And if that doesn't help, make sure that you have the PLUGIN version of Flash installed, not just the ActiveX version.
Chrome has built in flash.
IE uses ActiveX.
Firefox, Opera and other browsers use the plugin version.