Hi  !

Just to make sure, would you check this :

Type in the address bar about:config (press Enter) (promise to be careful, is asked)

Type and look for the preference :

browser.warnOnQuit'

its value should be set to true

You could also check your setting in :

Options => General => under 'When Firefox starts'

If you have checked 'Show your windows and tabs from last time' you won't get the warning dialog.

Happy112 said

Hi  ! Just to make sure, would you check this : Type in the address bar about:config (press Enter) (promise to be careful, is asked) Type and look for the preference : browser.warnOnQuit' its value should be set to true You could also check your setting in : Options => General => under 'When Firefox starts' If you have checked 'Show your windows and tabs from last time' you won't get the warning dialog.

I look through the about :config , I still cannot get the warning box appear, I need the old style three warning option (save and quit ,quit , close )appear, not just close tabs box.

On the about:config page, you could also make sure that the value of browser.showQuitWarning is set to true.

And then close and restart Firefox.