https://www.mozilla.org/en-US/firefox/organizations/faq/

You can't change the update channel by modifying the app.update.channel pref. The only way to switch the update channel is to install the full version.

See also channel-prefs.js in the "defaults/pref" folder in the Firefox program folder.

Not sure if changing this preference still works and if it did it works on going up a channel like say Beta to Aurora and not other way.

Easiest way to get on a channel is to download and install a build from that channel.

cor-el said

You can't change the update channel by modifying the app.update.channel pref. The only way to switch the update channel is to install the full version. See also channel-prefs.js in the "defaults/pref" folder in the Firefox program folder.

Hi cor-el, thanks for responding

Are you saying I can't change the update channel by modifying the file 'channel-prefs.js' file in the "defaults/pref" dir? That file is what I did change i.e. my file 'C:\Program Files (x86)\Mozilla Firefox\defaults\pref\channel-prefs.js' is currently

/* This Source Code Form is subject to the terms of the Mozilla Public

* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */

pref("app.update.channel", "esr");

I didn't change the value of 'about:config' param 'app.update.channel' as the web links indicated this value does not set the update channel - I viewed it's value and it was/is still 'release'

I had manually downloaded the FF ver 45.1.1 esr file 'Firefox Setup 45.1.1esr.exe' [~42.5MB] from mozilla site & installed it on top of the existing FF ver 44.0 on Win7 PC [all stuff in default directories suggested by installer]. When I run firefox, I am running the new version 45.1.1 as shown on attached 'about:support'

Any other suggestions on how to change to being on esr channel?

TIA M

Sounds that the channel-prefs.js didn't get replaced or that there is a problem with the app.update.channel pref.

• http://kb.mozillazine.org/Preferences_not_saved

You can check for problems with preferences.

Delete possible user.js and numbered prefs-##.js files and rename/remove the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in current Firefox releases.

• http://kb.mozillazine.org/Preferences_not_saved
• http://kb.mozillazine.org/Resetting_preferences

Hi

Figured out what needs to be done - the simple solution is to edit the 'channel-prefs.js' as above i.e. to enable 'esr' channel, edit 'C:\Program Files (x86)\Mozilla Firefox\defaults\pref\channel-prefs.js' to pref("app.update.channel", "esr");

But NOT create any other '.js' file in this directory e.g. backup files [which is what I had created]. It seems that firefox will read in all '*.js' files in this dir sequentially & you get the value of pref "app.update.channel" from the last file it reads

I established this by testing with Sysinternals 'Process Monitor'. Can see FF queries this dir for '*', it loops around all files reading each file [it skips directories and files that don't end with '.js' & '.JS'] e.g. I have attached file with one run - can see 1) directory query for '*', 2) 3 entries returned - 'channel-prefs.js', 'MyTest_channel-prefs.JS' & 'my_backup' [which is a sub-dir] 3) loops around reading the files in the order returned

The value of "app.update.channel" in the last file ['MyTest_channel-prefs.JS'] is what Firefox uses

Apologies for the dodgy highlighting!

Now, 'about:config', 'about:support' & 'Help/About' all now show as 'esr' and help doesn't suggest upgrading from this esr [45.1.0] to release [46.0.1] :-)

Not sure if other parts of Firefox read config files in the wildcard way, so careful what you backup!

Thanks for your help cor-el

M