Firefox 21 now tries to play MPEG media in <audio> and <video> tags using components of Windows Media Player. Perhaps there is a glitch on your XP system based on the version of Windows Media Player available???

To toggle this feature off and test the Flash fallback, try the steps in this thread: How to disable the built-in media player in FFv21?

Thanks for that. I followed the instructions, restarted Firefox, but I have the same result; blank screen when I try access this: http://demo.infysol.com/video-test.html

Yet, I can see the player and play the video on other computers, via Firefox (and you can too, probably on your computer).

HELP, please

If you check Firefox's Error Console (Ctrl+Shift+j, then click the Errors button to filter the list), are there any script errors (other than the one about the character encoding)?

If you right-click the blank area, do you get the Flash player menu?

Thanks for your reply. I appreciate any help.

After following your instructions, "other than the ones about the character encoding" , I see this (I've changed the url for this posting): Timestamp: 6/15/2013 10:52:18 AM Error: ReferenceError: $ is not defined Source File: http://www.url-url.com/ Line: 145

Even though that has nothing to do with not seeing: http://demo.infysol.com/video-test.html can you tell me what that error means, please?

And in regard to right-clicking the blank page, I simply see the word Silverlight in a small rectangle box.

Any additional help will be GREATLY appreciated. Much thanks

The error $ is not defined means that the jQuery library isn't loading correctly. The page is loading the library from Google rather than from the site itself.

When you have a problem with one particular site, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Bypass Firefox's Cache

Use Ctrl+Shift+r to reload the page fresh from the server.

Alternately, you also can clear Firefox's cache completely using:

orange Firefox button (or Tools menu) > Options > Advanced

On the Network mini-tab > Cached Web Content : "Clear Now"

If you have a large hard drive, this might take a few minutes.

(2) Remove your google.com cookies (save any pending work first). You can call up the cookie dialog anywhere on google.com using:

• right-click and choose View Page Info > Security > "View Cookies"
• Alt+t (open the classic Tools menu) > Page Info > Security > "View Cookies"

Or if you call it up from another site, change the site in the search box at the top of the dialog to google.com. Then you can remove your Google cookies individually.

Then try reloading the page. Does that help?

If jQuery still won't load, review your extensions for any designed to reduce cross-site interactions or targeting Google or privacy. You can review those here:

orange Firefox button (or Tools menu) > Add-ons > Extensions category

Correction to my last post: the script is loading from ajax.googleapis.com not from google.com.

Hi chrisjchrisj, you wrote:

And in regard to right-clicking the blank page, I simply see the word Silverlight in a small rectangle box.

That's very strange. The video should play in the native player (if the preferece media.windows-media-foundation.enabled is true) and in the Flash player if it's false. Oh, wait, you don't have Flash in your plugins list. Can you check here:

http://www.adobe.com/software/flash/about/

I was under the impression that the Windows Media Foundation stuff depended on the system running at least Vista, if not Win7. I didn't think XP had the proper codec support built-in.

Thank you again for your suggestions/info. I removed the cookies, tried the video player link again, but saw nothing (again). I reviewed my extemsions. There are three: Freemake video convertor plug-in - disabled. Microsoft.net Framework assistant - disabled and RealDownloader - disabled. I looked at your link: http://www.adobe.com/software/flash/about/ I don't know what I'm checking for. Any clarification would be appreciated, as would any additional suggestions. Much thanks

Hi KWierso, you wrote:

I was under the impression that the Windows Media Foundation stuff depended on the system running at least Vista, if not Win7. I didn't think XP had the proper codec support built-in.

This article agrees with you: About Media Foundation (Windows).

Hi chrisjchrisj, you wrote:

I looked at your link: http://www.adobe.com/software/flash/about/ I don't know what I'm checking for. Any clarification would be appreciated, as would any additional suggestions.

Do you have the Flash player plugin for Firefox ("Shockwave Flash") installed? Adobe's test page should tell you or lead you to a download page.