How can I stop ESR52 from slipping back to release v. 56?

[Odin2]

This has happened several times. The last time it was after a Windows update, when I dismissed a Fx popup by agreeing to make Fx my default browser [which was always my setting anyway]. I'm not sure whether the slip-back happened before or after I dismissed the popup. Any help would be appreciated.

[allande]

There are 4 reasons I can think of that Firefox ESR 52 would update to 56 or something in the Firefox line. 1 - bad files leftover in the updates folder 2 - another version of Firefox installed somewhere on the hard drive that can run sometimes, maybe from a leftover shortcut 3 - You have Firefox 52, not 52 ESR installed accidentally 4 - problem with the mozilla maintenance service
I hope that problems 1 through 3 can be fixed by doing this:
Download the 52 ESR Installer.
Uninstall Firefox.
Go to program files \ mozilla firefox and make sure it is deleted, delete if necessary.
Go to program files(x86) \ mozilla firefox and make sure it is deleted, delete if necessary.
Install Firefox 52 ESR.
If you still see it happen after that, disable the maintenance service by renaming its exe's.

[Odin2]

Thanks, allande. I'll give it a try.

[James]

Firefox 52 ESR is at https://www.mozilla.org/firefox/organizations/all/

A version on ESR channel will not update to a version on Release channel. The 52.0.1 and 52.0.2 were Release versions.

Another possibility is you have both 52.6.0esr and 56.0.2 Release installed.

[ineuw]

James, unfortunately if one places a symlink in usr/bin that points to an ESR installation, Firefox update will follow the link and replace the ESR version with the latest Firefox. I resolved the issue as follows:

• Regardless of the version, the profile folder is always in the home directory, and if you are doing a backward version install, (from 58+ to 52), I would first export the bookmarks and the passwords.
  * Block the repository version in Synaptic, as outlined above.
  * Download the preferred Firefox version from https://ftp.mozilla.org/pub/firefox/releases/. This downloaded file is a compressed .tar.bz2 archive is found where the browser's download folder is specified. The default is the ~/Downloads folder.
  * Extract the archive with an archive manager which creates a fully functioning fiefox ~/Downloads/firefox folder. and the firefox-nnn.tar.bz2 archive can now be deleted (or stored in a software storage folder).
  * Move ~/Downloads/firefox folder from ~/Downloads to /opt: sudo mv ~/Downloads/firefox /opt/firefox52.6ESR. (my choice)
  * Firefox has two binary files, either of which will start browser. They are /firefox and /firefox.bin.
  * Replace the symlink in /usr/bin which points to the standard repository installation with a symlink pointing to the /opt insallation: sudo ln -sf /opt/firefox52.6ESR/firefox.bin /usr/bin/firefox.
  * For a good measure, I also deleted the two folders of the repository installation: sudo rm -R /usr/lib/firefox and sudo rm -R /usr/lib/firefox/extensions.