I am looking for a solution like this: https://support.mozilla.org/en-US/questions/753852

But this one does not apply to the current version anymore

Type about:preferences#advanced<enter> in the address bar. Under Advanced, Select Update.

[v56+]; Type about:preferences#general<enter> in the address bar. Select Update.

Check the settings. "Check for updates, but let you choose whether to install them"

Also turn off Use a background service to install updates <Windows Only>

Note: The setting to never check for updates was removed

How do you completely turn off update checks in Firefox v64? You can use a policies.json file to disable updates for all users. https://github.com/mozilla/policy-templates/blob/master/README.md

I am running version 68.0.1 64bit. There is no setting like "Check for updates, but let you choose whether to install them", I only get to chose whether to update search engines.

Do your settings look like this?

No, sadly it looks like this

I just noticed, my Firefox is managed by apt. So it's all my fault ^'_^

What is managed by apt?

Firefox has been installed from packages. apt unattended upgrades ran in the background and I got a bit mad because having to restart Firefox lost me some of my work.

Back up and restore information in Firefox profiles.{web link} I use an add-on that makes backups of my user profile, Just In Case. Unfortunately, it is not compatible with the current Firefox.

Every now and then, open the profile folder and create a copy of the current profile as is to another location on your hard drive. This way you will have a backup.

If you do this each day, you will not lose much data. This should be done with Firefox Closed.

Note: In case you need to restore from these backups, you may need to overwrite old or corrupted files.