In what location did you install the DE version ?

If this is in an location that requires root privileges in order to install update then you need to launch Firefox via a 'sudo' command to be able to update from within Firefox via "Help -> About Firefox". To avoid this you can install Firefox in your home directory (~/firefox).

Note that Beta and DE update twice a week and Beta gets release candidates as final updates while DE pauses until the next major update.

Thanks for response, cor-el. At present, I have FFDE installed in /opt, its launch softlink in /usr/local/bin and the launcher icon for the Show Applications array within /usr/share/applications.

Looking at my file system I see that for the two users on this PC (Admin and myself) there is a .mozilla folder in both /home/<user> folders. This folder presumably holds the regular (i.e. non Developer Edition) Firefox browser and, being in both home folders, it is available independently to both users and can be updated automatically without root privileges when opened by either user.

How about putting Mozilla Firefox Developer Edition into some /usr directory? This is the customary location for applications available to all users. Hopefully, all users could access this and duplication of installation would be avoided. The user preferences and bookmarks could also be shared since I am also the Admin.

With Firefox DE installed in /opt you either need to update via Ubuntu software management or, like i wrote above, by starting Firefox via 'sudo' with root permission or by installing the full version.

The "~/.mozilla" location is used as the primary location for the Firefox profile folder and not for installing Firefox program files.

Firefox uses two locations for the Firefox profile folder. One location for your personal data (e.g. bookmarks) and another location for temporary files like the disk cache, so make sure to look in the correct location.

Location used for the main profile that keeps your personal data (Root Directory on about:profiles).

• ~/.mozilla/firefox/

Location used for the disk cache and other temporary files (Local Directory on about:profiles).

• ~/.cache/mozilla/firefox/

Thanks for reply, I downloaded the DE in /home/.firefox/firefox folder. And it worked. Earlier I had downloaded it in /opt/firefox

With Firefox DE installed in /opt you either need to update via Ubuntu software management or, like i wrote above, by starting Firefox via 'sudo' with root permission or by installing the full version.

Starting Firefox with root permission is only possible in Admin account - and people seldom (for security reasons) use this account for normal browsing.

Installing the full version . . . I was under the impression that I had installed the full version, i.e. FFDE independent of any existing FF version. I'll try putting it in an accessible folder.

Works when installed in /usr/local. No annoying pop-ups about updates so far. Many thanks, cor-el.

Updates for DE are halted at the moment because Firefox 88.0 has been finalized and is in release candidate state (currently RC2).

• http://forums.mozillazine.org/viewtopic.php?f=23&t=3073934

In this case only Beta gets updates and DE will get updates once 88.0 has been released and the first 89.0b1 version is available, so you will see update for DE either later this week or next week Tuesday and then twice a week until 89.0b9 and then it stops again for about two weeks.

Back to pop-ups "unable to update" again . . . Looks like putting the package into /usr/local won't allow auto updates.

I don't see why updates work smoothly and automatically with Firefox standard version but have to be manually applied in FFDE . . .

If there is a directory allowing auto updating of FFDE, please tell me where it is. Not 4 answers, just one - one that will work.

Any directory in your home folder (e.g. ~/firefox) will work like I posted above in my first reply. If you install Firefox in a location like '/usr' or '/opt' then you need to use a terminal window and use 'sudo' to start Firefox with root permissions (do not login as root user).

Did it and cannot describe my relief to see the update process finally working unaided. Just curious - why didn't Mozilla make Firefox Dev Ed a separate package on Ubuntu's apt installer ? Would apt really insist on sharing of common dependencies and thus prevent independent versioning of FF and FFDE ? Was there no workaround for this ?

tamjk, I had installed firefox DE in ~/.firefox folder, and it solved the issue, because I copied the outdated firefox DE to that location and it since haven't asked me to update. It probably can't be put in Ubuntu official repos as it updates very frequently. Most of the software I see in ubuntu official repos is mostly outdated. However, it would be easier to install if firefox DE would have an official PPA, or flatpak or snap package.

I'd like a PPA for FFDE too. Even a snap would be better than manually updating.