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Why did Firefox disable my antivirus?

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  • 4 have this problem
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  • Last reply by James

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Got a message that my Kaspersky protection was disabled because "Kaspersky protection could not be validated for use in Firefox." Huh? Going to have to go back to Chrome if this can't be fixed quickly and easily.

Got a message that my Kaspersky protection was disabled because "Kaspersky protection could not be validated for use in Firefox." Huh? Going to have to go back to Chrome if this can't be fixed quickly and easily.

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This is an issue with Kaspersky. Their addon has not been signed. Firefox automatically disabled unsigned addons for user security.

Please refer to these Mozilla articles for more information about unsigned addons and how to enabled them:

Warning: The steps above may present a security risk. Please use with caution and at your own risk.


Please consider advising the addon developer about the issue, so that they can get their addon signed as soon as possible.

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The completely separate Kaspersky anti-virus software installed on your Windows 10 is not touched in any way by this and should still be functioning normally.

The Kaspersky extension needs to be signed.

A workaround to try for Firefox 43.0 until Kaspersky fixes their extension is to type about:config in Location (address) bar. Filter for xpinstall.signatures.required and double-click the preference, or right-click and selected "Toggle", to set it to false.