Did you make sure to read the next section in that article with regard to extensions.enabledScopes ?

Also, you may need to put the file in the /defaults/pref subfolder of the program folder if you had not, or the pref would be ignored if I read that well from this article (see its comments.)

There is also this bug that might be worth following, though there hasn’t been much activity until now.

Tonnes said

Did you make sure to read the next section in that article with regard to extensions.enabledScopes ? Also, you may need to put the file in the /defaults/pref subfolder of the program folder if you had not, or the pref would be ignored if I read that well from this article (see its comments.) Yes !, like I wrote there that I copied the JS to every single place available for Firefox to try getting it work. and I did the following section. Bedsides. my preferences do change except for the disable scope, Which means the customized preferences file does work. and problem is only with the Disable Scope There is also this bug that might be worth following, though there hasn’t been much activity until now.

Can you post the content of the mozilla.cfg file?

"Every single place" is probably the issue.

I wrote /defaults/pref above, but the .js file should reside in the [Program folder]\browser\defaults\preferences folder for extensions.autoDisableScopes to work. Other preferences may work at other places, this one apparently does not. If the subfolder does not exist, just create it.

Also see here.

When I say i put it in every single place I didn't mean in the same time I tried to see if it works in different places not multi (I tried that later) again guys the configuration file works! I managed to change preferences just not the DisableScope.

the content of my file is : // Extension Settings pref("extensions.autoDisableScopes", 0); pref("extensions.enabledScopes", 15);

Tonnes said

"Every single place" is probably the issue. I wrote /defaults/pref above, but the .js file should reside in the [Program folder]\browser\defaults\preferences folder for extensions.autoDisableScopes to work. Other preferences may work at other places, this one apparently does not. If the subfolder does not exist, just create it. Also see here.

It seems to be working in the Default\preferences like you said. Can I put all my preferences in that location?

Glad to see it’s working.

Of course I did not assume you used the same place every time, the point was just that we can’t "smell" which places you tried exactly (similar to when someone says "I have read all the instructions" ;-) ), so there is nothing wrong with asking in my first post, though I should have provided the proper place there.

I think you can put the other preferences on that location too, yes, but don’t expect they will all work - you should probably try / check each one of them for proper operation. Keep in mind that a) some preferences were added in later Firefox versions, probably causing them to work at one place and not the other like this one, and b) the order of places being read at startup is important, so if you add prefs on multiple places, one could override the other. Luckily, Mike Kaply’s articles are quite helpful with regard to that. The first link I provided unfortunately only mentions "the defaults/preferences file" in a comment, which may have been confusing. Also, info about some directory structure changes made is not included in the MDN doc’s link you provided, but it is in this one. Reading that, I’m pretty sure some prefs may also no longer work on one place and require to be moved. From MDN: Custom settings in defaults/pref that worked in a version of Firefox before 21 may fail in a current or future version. If this happens, copy or move your customized files into the corresponding directories in browser/defaults/preferences and redeploy. I’m sorry if this lead to any confusion.

thank you for your help !!  :)