Check Your Adobe Flash player is up to date or not.

You can check it from Mozilla's plugin checker page. If it is an old version and vulnerable, please update it.

And do let us know, are You getting any error Messages while trying.

adobe flash is up to date.. still the same problem with no error messages or any kind of notification!

Try Firefox Safe Mode to see if the problem goes away. Safe Mode is a troubleshooting mode, which disables most add-ons.

(If you're not using it, switch to the Default theme.)

• You can open Firefox 4.0+ in Safe Mode by holding the Shift key when you open the Firefox desktop or Start menu shortcut.
• Or open the Help menu and click on the Restart with Add-ons Disabled... menu item while Firefox is running.

Once you get the pop-up, just select "'Start in Safe Mode"

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, and you need to figure out which one. Please follow the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article for that.

To exit the Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.

When you figure out what's causing your issues, please let us know. It might help other users who have the same problem.

Thank you.

Can you post a link to that website or the code that you use for the Flash objects?

the website isn't hosted yet.

But, this is the auto-generated code for inserting a flash using Dreamweaver:

<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" width="581" height="313" id="FlashID2" accesskey="F1" tabindex="1" title="afterearth">
          <param name="movie" value="afterearth.swf">
          <param name="quality" value="high">
          <param name="wmode" value="opaque">
          <!-- Next object tag is for non-IE browsers. So hide it from IE using IECC. -->
          <!--[if !IE]>-->
          <object type="application/x-shockwave-flash" data="afterearth.swf" width="581" height="313">
            <!--<![endif]-->
            <param name="quality" value="high">
            <param name="wmode" value="opaque">
            <!-- The browser displays the following alternative content for users with Flash Player 6.0 and older. -->
            <div>
              <h4>Content on this page requires a newer version of Adobe Flash Player.</h4>
              <p><a href="http://www.adobe.com/go/getflashplayer"><img src="http://www.adobe.com/images/shared/download_buttons/get_flash_player.gif" alt="Get Adobe Flash player" width="112" height="33" /></a></p>
            </div>
            <!--[if !IE]>-->
          </object>
          <!--<![endif]-->
        </object>

That code looks OK to me, although a bit weird (IE would see the param tags twice because only the object tag is hidden via the conditional code).

Do you at least see an empty space where the flash object should be?

Does the Flash object work if you paste its full URL in the location bar?

well, the code is auto-generated and i have only a simple experience with coding..! and yes there's an empty space where the flash object should be.

Does the Flash object work if you paste its full URL in the location bar without inserting it in Your html page?

I mean is it working alone?

Did You linked all components correctly? Like if You have any separate Action Script file running for Your flash animation.

Can you confirm that you see the Flash player if you right-click?

Try to start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

• Do NOT click the Reset button on the Safe Mode start window or otherwise make changes.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

And I tried adding the Full URL for the flash object and now surprisingly the flash object isn't working on all browsers including the IE.

in the previous replay, I added the Full URL in the dreamweaver flash properties.

the flash object is working perfectly as a standalone...

Did You use site Management feature in Dreamweaver?

If it is not, please create a New site under Site > New Site...

Your problem must be a mislinking issue. Make sure, Your path is correct.

While creating New site make sure all Your files are in the same route folder.

Then remove all Your Auto generated codes and links to the flash objects. Try to insert Your .swf file again from scratch.

Did you make sure that the afterearth.swf file is on the server in the expected location?

You can check the HTTP response headers in the Web Console (Firefox/Tools > Web Developer;Ctrl+Shift+K).