Avast may block Thunderbird updates

Martin Brinkmann
Oct 18, 2022

Avast and AVG antivirus products may block updates in Thunderbird. Avast is testing a beta version of its applications that attempts to resolve the issue.

thunderbird 102
image credit: Thunderbird

Users of Avast and AVG antivirus solutions that use the open source email client Thunderbird may face another problem. Earlier versions of Avast and AVG products on Windows caused severe crashes of the Firefox web browser earlier this month. Mozilla had to rush a release, blocking older drivers of the antivirus solutions to prevent crashes in the Firefox web browser.

Now it is Thunderbird. This time, it is not crashes that Avast and AVG software is causing, but issues with the email client's updating system.

The Mail Shield component of Avast and AVG products, designed to block malicious emails from reaching a user's inbox, appears to be the culprit. The Thunderbird team confirmed the issue on its Twitter account, stating that the issue is caused by connection issues of Avast's and AVG's Mail Shield component.

Sören Hentzschel discovered that the issue dates back to at least July 2022. A user published a bug report on the Avast Forum, stating that Avast blocked automatic updates in Thunderbird.

Avast is testing a Beta version at the time, but has not published a stable new update that addresses the issue.

Thunderbird users may want to check the installed version of the email client to find out if they are affected. The latest version, at the time of writing, is Thunderbird 102.3.3.

thunderbird avast issue

Thunderbird users who are affected by the issue may disable the Shields component of the Avast or AVG software temporarily to update Thunderbird. Selecting Menu > Help > About Thunderbird should download and install the latest version once Shields are down.

Another option that users have is to uninstall Avast or AVG software on their device. On Windows, fallback is provided by Microsoft Defender.

Avast has not revealed a release date for the fixed version. The beta version was released on September 22.

Now You: which security solution do you use on your machines?

Avast may block Thunderbird updates
Article Name
Avast may block Thunderbird updates
Avast and AVG antivirus products may block updates in Thunderbird. Avast is testing a beta version of its applications that attempts to resolve the issue.
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  1. Anonymous said on October 20, 2022 at 8:28 am

    Avast used to be good in proctecting pc, but it’s only adware/malware now..

    Avast intercepts internet connection and steal data(search “avast ssl injection” for more info).

  2. Anonymous said on October 19, 2022 at 4:22 pm

    Avast, the security company we love. Not just endangering our private data by selling it, a move so bad that even Google frowned at it, but also blocking software updates (today thunderbird, yesterday windows…), preventing security updates to be installed.

  3. Ewil said on October 18, 2022 at 6:12 pm

    Anyone heard of Avast AV blocking and removing even one actual, real virus these last 10 years?
    Didn’t think so.. Avast is all about bogging down your computer, advertising their premium services 24/7 and blocking useful and harmless files non-stop. Undisputed champion of false positives and main culprit in 99,99% of cases where something is not functioning properly. Avast is the worst thing you can do to your computer, software-wise.

  4. alabaster sam said on October 18, 2022 at 4:01 pm

    I started out using Avast av many years ago, then dumped. I’ve used BitDefender (their best paid version) for a few years now and seems excellent.

  5. Phil said on October 18, 2022 at 3:59 pm

    Because NortonLifeLock purchased Avast

  6. Paul(us) said on October 18, 2022 at 11:47 am

    For 22 years now Eset products. First Eset NOD32 Antivirus and later ESET Internet Security,
    One of their really great features is their heuristic scanners who will run suspicious files in an in-product sandbox to observe their behavior and assess their risk, meaning that even previously unknown malicious code can be detected. And there is much more to love for me.


    1. Frankel said on October 19, 2022 at 10:24 pm

      The site you link gives AVAST best scores. I guess I pass on their “advice”.

  7. 1337 said on October 18, 2022 at 7:32 am

    I remember way back in A+ class when we were supposed to install this dumpster fire on our install rigs. I warned the instructor “don’t do it” and he laughed. He wasn’t laughing after ~20% of the students computers hosed and had to reinstall. Weird thing is we couldn’t figure out why all of them didn’t hose.

    1. John G. said on October 18, 2022 at 10:45 am

      I use MS Defender, however configured with Configure Defender 3.111, setting to high. No problem. Anyway it hasn’t an option to clear the history of malware detected.

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