Firebug is not working with Firefox version 50.0

Question

I am using Firefox 50.0. After auto update of Firefox to version 50.0, Firebug has stopped working and attempting to use it is showing an inbuilt Firefox console while inspecting any DOM element.

Is there any patch to use Firebug on Firefox 50.0 version?

Answer 1

Firebug does not work with multiprocess Firefox

The Firebug site claims that:

Firebug 2.0.18 is compatible with Firefox 30 – 52

However, it also explains that [emphasis mine]:

Firebug 2.0.18 fixes issue 8030. The extension is marked as multi-process (e10s) compatible so, it isn’t blacklisted and users can continue installing it. This way Firebug can help users to easily migrate into built-in Firefox developer tools – in case it’s running in multi-process enabled browser. When opened in a multi-process Firefox, Firebug’s tools cannot be used. Firebug will then only assist the user with migration to Firefox’s built-in tools.

They also direct you to read: Unifying Firebug & Firefox DevTools

That page says that [emphasis mine]:

Firebug 2 doesn’t work in multi-process browsers (i.e. e10s) and converting it is too complex, so it will stop working when e10s is activated in Firefox. You will be able to disable e10s for a while to keep using Firebug 2, but this won’t last forever.

The fact that Firebug does not actually work in multiprocess Firefox will account for different people having different experiences with Firebug working or not working in a particular version of Firefox. Firefox automatically enabling multiprocess mode will depend on multiple factors, including what other add-ons are installed in the profile.

Using Firebug in newer versions of Firefox

Thus, to use Firebug in newer versions of Firefox, you will need to disable Firefox from entering multiprocess mode. This can be done from the about:preferences page (also available from Tools➞Options). This an option which is under the "General" tab as "Enable multi-process Firefox ...". If multiprocess is not available, this option will not be shown. This option can also be changed by adjusting the preference browser.tabs.remote.autostart from about:config. [Note: browser.tabs.remote.autostart.2 and browser.tabs.remote.autostart.1 also appear to be used to indicate default states, thus I suggest using the about:preferences page to change this option.]

You can determine if your Firefox is currently running in multiprocess mode by looking in about:support. The line "Multiprocess Windows" under "Application Basics" will state if multiprocess is enabled or disabled.

Set up profiles explicitly for testing

Personally, I have different profiles set up for each of multiprocess explicitly disabled and multiprocess explicitly enabled (set browser.tabs.remote.force-enable to true), so I can perform testing under both conditions, with the state of multiprocess being enabled/disabled being known in advance.

Answer 2

I had the same problem when I updated Firefox. I was so addicted to firebug but I moved on to Firefox developer edition - https://www.mozilla.org/en-US/firefox/developer/

It also comes with the firebug theme which resembles firebug UI and its efficient.Just install FDE and activate the firebug theme as shown in the image below :

Answer 3

I managed to resolve this issue by simply downgrading to mozilla old version using this url:

• open https://ftp.mozilla.org/pub/firefox/releases/50.0/win64/en-US/
• download and run the .exe setup
• Go to Settings - > Add Ons
• Click on extensions and search for firebug and firepath and then add those extensions

Hope this should resolve the issue. For those using Windows 32 machine can use the url https://ftp.mozilla.org/pub/firefox/releases/50.0/win32/en-US/

Answer 4

Head over to Firebug website, you can see following message:

The Firebug extension isn't being developed or maintained any longer. We invite you to use the Firefox built-in DevTools instead.

Also Sebastianz told me,

Firebug is discontinued. The team has split up, the former team leader Jan "Honza" Odvarko is working on the Firefox DevTools now.

As @Makyen said in his answer, Firebug does not work with multiprocess Firefox, so remove Firebug right now and try Firefox DevTools instead, it's not optional (sadly), unless you don't update Firefox :)

Update 1

Take a look @ Why got Firebug removed after updating Firefox to version 50?

Update 2

Take a look @ my answer here: how to revert firebug to old version

Answer 5

http://toolsqa.com/selenium-webdriver/xpath-helper/

Open a new tab and navigate to any webpage. I have used www.DemoQA.com for demo. Hit Ctrl-Shift-X (or Command-Shift-X on OS X), or click the XPath Helper button in the toolbar, to open the XPath Helper console. Hold down Shift as you mouse over elements on the page. The query box will continuously update to show the XPath query for the element below the mouse pointer, and the results box will show the results for the current query. If desired, edit the XPath query directly in the console. The results box will immediately reflect your changes. Repeat step (2) to close the console.

Answer 6

I manage to get Firebug work again, so here is what I done.

Everyone knows that Firebug isn't being developed or maintained any longer because it can't work with e10s, so here is my workaround:

• Download Firefox Developer edition so you can allow XPI installation.
  firefox-53.0a2.en-US.win64.installer.exe or firefox-53.0a2.en-US.win32.installer.exe

• Run Firefox developer edition after installing and go to the about:config (type in url bar)
  Find xpinstall.signatures.required (set to false)
  Find browser.tabs.remote.autostart
  (set all to false: browser.tabs.remote.autostart.1 and browser.tabs.remote.autostart.2)

NOTE: The Multi-process architecture improves the browser's stability, performance and security by separating tasks into processes, you disabling it at own responsibility.

After that you need to restart the browser.

• Now you can go at the Firebug repository and install desired version
  Here you can find all Firebug installations

I chose latest firebug-2.0b8.xpi and it forking fine.

P.S. You can disable updates for Firefox Developer edition.
Hope it helps.