You need to place code for about pages in userContent.css and not in userChrome.css. userChrome.css is for the user interface.

@-moz-document url(about:newtab){
 #newtab-margin-top,
 #newtab-margin-bottom,
 #newtab-search-container {display:none!important}
}

cor-el said

You need to place code for about pages in userContent.css and not in userChrome.css. userChrome.css is for the user interface.

Thank you but still not working (see screenshot) !

This is the currently used profile folder as the name doesn't have a random name? Did you create this folder yourself? Does any other code in either file work?

You can use this button to go to the current Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Did you create this folder yourself?

- Yes !

Does any other code in either file work?

- No other code on userContent.css

- Code on userChrome.css https://github.com/manjaro/.../chrome/userChrome.css

EDIT: Searching... i have find this bug https://bugzilla.mozilla.org/show_bug.cgi?id=1046166

That bug refers to a multiprocess feature that is turned off in Firefox 42 by default. Have you turned on e10s in Firefox 42? If you have, the Stylish extension may work with e10s enabled, according to this page: http://arewee10syet.com/

Hi, the easiest way is to use the add-on New Tab Tools.

If your question is resolved by this or another answer, please take a minute to let us know. Thank you.

jscher2000 said

That bug refers to a multiprocess feature that is turned off in Firefox 42 by default. Have you turned on e10s in Firefox 42? If you have, the Stylish extension may work with e10s enabled, according to this page: http://arewee10syet.com/

Thanks for the tip but i dont have Stylish extension ! Later i will reset firefox to the defaut settings and test again.

Did you check the browser.tabs.remote.autostart prefs on the about:config page?

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

• http://kb.mozillazine.org/about:config

@cor-el browser.tabs.remote.autostart is set to false.

@jscher2000 @cor-el i have backup my profile, start/close Firefox to create new one and test again with userContent.css and it is perfectly working !

After that i have reinstall/cofig my addons and restor my bookmark/password from my old profile :)

Solved! Thanks very much to all helping me for fixing this problem.

Regards, Med