Today i have installed a new version(52) of firefox in machine and add the extension firebug .but it not showing in toolbar. i have restarted several times still no luck and then again i have installed ,intstallation gets success,not showing in toolbar.
Again I have customize and enable the firebug but when I clicked it's not responding and showing the firebug inspect tool.
On 17-3-2017 uninstalled and installed the 52 version of firefox and add firebug but it not showing there?
see the screenshot below.
The problem is happen only in the version.Anybody have idea.
Firebug is officially discontinued. New installations of Firefox have multi-process enabled. With that the Firefox DevTools are opened instead of Firebug when you click the Firebug button and a notification is shown giving a short explanation:
You can get Firebug back by deactivating the multi-process feature, though this is only a short-term solution, as multi-process will be mandatory at some point.
Firebug is (sadly) no longer updated, or supporting latest Firefox versions.
If you like Firebug and Firefox, then you can use:
- Waterfox 55 (based in FF56)+ Firebug 2.0.19 (install extension and restart)
- Palemoon 27.6 (based in FF pre Australis and FF52 upgrades) +firebug 1.12.8.1
- An oudated and non supported Firefox
Waterfox and Palemoon are active projects, and they will continue supporting classic Firefox extensions/addons
来源：https://stackoverflow.com/questions/42834636/firebug-is-not-working-on-mozilla-version-52