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Mozilla stops rollout Firefox 65 after reckless website blocking

Mozilla stops rollout Firefox 65 after reckless website blocking

Firefox 65, which was supposed to provide extra privacy by blocking trackers, is at odds with antivirus software that blocks far too many websites. Mozilla withdraws the update pending a solution.

With Firefox 65, Mozilla pulled the privacy card. The latest version of the browser should protect users by blocking tracking, as well as giving surfers the option to more accurately control what they want to share. It seems that the filter used for this purpose has an unexpected side effect. If you use Firefox 65 in combination with Avast or AVG, you will notice, according to various sources, that websites are suddenly no longer accessible.

The sites seem to be random, but the error does not discriminate. Big websites like Twitter are stopped, just like little ones. Anyone who tries to visit a site runs into the SEC_ERROR_UNKNOWN_ISSUER error message. In other words, Firefox (wrongly) indicates that a connection to a site is not safe. The way in which HTTPS scanning in the antivirus software works together with Firefox 65 is at the heart of this.


Mozilla will stop the rollout of its browser’s update until the problem is resolved. Those who have already downloaded Firefox 65 can disable HTTPS scanning in their antivirus suite, or require Firefox to automatically trust all certificates in the Windows Certificate store. Do the latter by surfing to about:config and setting security.enterprise_roots.enabled to true.

The problem only affects Windows users. Other antivirus suites may also cause problems. If you use Firefox and suddenly you don’t get to your favorite website anymore, then you know the culprit. When the problem will finally be off the job, and Mozilla continues the rollout of Firefox 65, is still unclear.

Related: Firefox will block all tracking on websites by default

This news article was automatically translated from Dutch to give Techzine.eu a head start. All news articles after September 1, 2019 are written in native English and NOT translated. All our background stories are written in native English as well. For more information read our launch article.