Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

I need to install Google Widevine on my Windows 7, Firefox browser, but it does not work.

more options

I tried various sources but I always get this answer: The add-on downloaded from this site could not be installed because it appears to be corrupt.

I use Norton security.

I am at lost what to do.

I tried various sources but I always get this answer: The add-on downloaded from this site could not be installed because it appears to be corrupt. I use Norton security. I am at lost what to do.

All Replies (3)

more options

A few users have reported issues with downloading addons from external sources. Please try the following:

  1. Go to the Widevine download page
  2. Right click the download link for Firefox on Windows
  3. Select Save link as... to save the XPI file to your hard drive
  4. Go to the Firefox addon manager or about:addons
  5. Click the gear icon
  6. Select Install addon from file...
  7. Open the XPI file when prompted

This should install the addon and it should be functional. If not, let us know.

Note: Once the addon has installed successfully, you may delete the XPI file that you downloaded.

more options

Thank you but although I followed your steps I get exactly the same response.

more options

It could be because this addon is not signed. Signing in an automated process that checks for potential threats. To protect our users' security, all unsigned addons have been blocked from running in Firefox.

To allow unsigned addons, please try the following:

  1. Go to about:config
  2. Locate the xpinstall.signatures.required boolean
  3. Change the value to false
  4. Try installing the addon, via the website
  5. If that doesn't work, try install the addon by using the steps in my previous post