The auto update is the default, but can be set to not do that. Older versions are available at https://ftp.mozilla.org/pub/thunderbird/releases/ - I suggest making a copy of the profile folder at the ...appdata\roaming\thunderbird folder, uninstalling the new version, installing your preferred version, and setting the auto update to no. You may need to remove a compatibility.ini file in the profile if you get message of incompatibility.

David, thank you for that but my point is that I had auto update turned off! It's been turned off for years because every update was rendering QuickText incompatible.

It's possible you have a security app like Norton that includes an updater that overrides the setting in TB.

https://support.norton.com/sp/en/us/home/current/solutions/v20240108182413203?

There is a version of Quicktext for TB 140: https://support.mozilla.org/en-US/questions/1521896

If QT is the only add-on you need, it's probably better to stick with 140 instead of downgrading to an older version.

Thanks everyone. I use AVG and I couldn't find anything that would overide a setting not to automatically upgrade. In any case I can live with TB 140 because the workaround to download the Quicktext install file in a browser other than Firefox did the trick. I'm happy now. Thanks again.

So, you believe the AVG Updater is not active on your system?

Are you talking about the Driver Updater? That's the only AVG Updater I have.

The Driver and Software updaters are separate.

Finally found the software updater and it was set to manual. There is a recommendation to update TB but it hasn't actioned. In any case TB 140 and Quicktext are running happily.

And you can get the latest prerelease of version v6.3.6 out today at https://github.com/jobisoft/quicktext/releases/tag/v6.3.6. You can download the xpi file, and in Thunderbird use Add-ons, click the gear icon, and choose "Install from file" to pick the downloaded xpi file.

FYI the delay has been that, for various reasons, Quicktext is being rewritten. The most important reason is to change it to pure Webextensions (well documented by our excellent add-ons support developer), which means it will be far less sensitive to Thunderbird version changes.

The author informs me that once this rewrite is complete then the community can more easily contribute code. For now, the best way to help is to test quicktext v6 using the instructions at https://github.com/jobisoft/quicktext/issues/439.

Thanks Wayne That's good to know.