Please ensure that the QuickTime player is enabled on your browser. To do so, please follow these steps:

1. Open the Firefox addons manager
2. Click Plugins in the sidebar
3. Located the QuickTime plugin
4. Select Always Activate or Ask To Activate from the drop down menu

Depending on the setting that you have selected, a website may prompt you for permission to use the QuickTime plugin. You can allow a website to have access to QuickTime, by clicking the plugin button (looks like a building block) on the left side of the address bar.

Please check if all your plugins are up-to-date. To do this, go to the Plugin Check site.

Once you're there, the site will check if all your plugins have the latest versions. If you see plugins in the list that have a yellow Update button or a red Update now button, please update these immediately.

To do so, please click each yellow or red button. Then you should see a site that allows you to download the latest version. Double-click the downloaded file to start the installation and follow the steps mentioned in the installation procedure.

Note: If your version of a plugin is newer then the one shown by the test page, do not worry about it. This just means the plugin you have is a recent update.

If the updater shows Unknown, this plugin is not on the testers list. To check that plugin, go to the home web site of the owner of that program.

Hi Wesley,

i have tried the steps before, it does not seem to work at all.

Sorry to hear that. Can you please try completely removing QuickTime from your system and then installing a fresh copy of the software from Apple?

Hi Wesley,

i have found out what the issue is, it not the quicktime or the firefox issue, it seem to be malware problem. do you know how to clear all the malware that is affecting firefox.

For malware issues see Troubleshoot Firefox issues caused by malware

For QuickTime plugin issues, see this article:

• Use the QuickTime plugin to play audio and video.

Note that installing or updating to QuickTime version 7.7.9 or above may remove the web browser plugin that sites like http://trailers.apple.com/ require. You can add the browser plugin by following the steps given in the Use the QuickTime plugin to play audio and video article.

You can try these free programs to scan for malware, which work with your existing antivirus software:

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• Anti-Rootkit Utility - TDSSKiller
• AdwCleaner (for more info, see this alternate AdwCleaner download page)
• Hitman Pro
• ESET Online Scanner

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one. Windows 8 has antivirus built-in already.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.