Web Control extension not available in Firefox 74 and later

Technical Articles ID: KB92605
Last Modified: 6/10/2020

Environment

McAfee Endpoint Security (ENS) Web Control 10.x
Mozilla Firefox 74 and later

Problem

The ENS Web Control extension does not appear in the Firefox 74 and later extensions list for new installations. ENS Web Control does not display any error to the client.

System Change

New installation of Firefox 74 or later.

Cause

Firefox 74 and later blocks extensions that do sideloading. The ENS Web Control extension uses sideloading in the Firefox browser.

For more information, see this Mozilla statement on discontinuing sideloading: https://blog.mozilla.org/addons/2019/10/31/firefox-to-discontinue-sideloaded-extensions/.

Solution

Use Active Directory to install the ENS Web Control extension. Firefox provides ADMX templates that you can use to configure an Active Directory policy to enable the ENS Web Control extension. For instructions, see KB87568.

Workaround

Firefox 73 and earlier with the ENS Web Control extension enabled can be upgraded to Firefox 74 and later and retain the ENS Web Control extension.

To install the ENS Web Control extension:

Deploy ENS Web Control on the endpoint.
Uninstall Firefox 74 or later from the endpoint.
Install an older version of Firefox 73 or earlier. The ENS Web Control extension is installed automatically.
Upgrade to Firefox 74 or later. The ENS Web Control extension continues to work in the browser.

Affected Products

Endpoint Security Web Control 10.7.x
Endpoint Security Web Control 10.6.x
Endpoint Security Web Control 10.5.x (EOL)
Known Issue/Product Defect

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Knowledge Center

Web Control extension not available in Firefox 74 and later

Environment

Problem

System Change

Cause

Solution

Workaround

Affected Products

Languages:

Glossary of Technical Terms

Title

Title

Knowledge Center

Web Control extension not available in Firefox 74 and later

Environment

Problem

System Change

Cause

Solution

Workaround

Affected Products

Languages:

Glossary of Technical Terms

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