No Prompt in Firefox Browser Console?

Question

I'm using Firefox for Ubuntu, version 39.0. I'm trying to debug an add-on and would like to run some JavaScript under chrome privileges. According to this page I should be able to do this in the Browser Console.

If I click on Tools -> Web Developer -> Browser Console in the Firefox menu, I get the Browser Console:

Only problem is, I can't evaluate anything. My question is: where's the prompt? Apparently this window should have a prompt. Things I have tried:

• Restarting Firefox with add-ons disabled (safe mode)
• Starting Firefox as a sudo user

Any tips?

Obedience

You have to enable developer preferences: developer.mozilla.org/en-US/Add-ons/… – Unmindful

Legend, I set devtools.chrome.enabled to true and that was it. Submit an answer if you like and I'll mark it as accepted. – Obedience

Awesome Sammy thanks for that specific preference share, I didn't know it was exactly that one. – Unmindful

Answer 1

You have to enable developer preferences:

"Setting up an extension development environment" MDN page from

• archived by Wayback Machine
• archived by Unified XUL Platform MDN Backup

Thanks to your research it looks like it was the devtools.chrome.enabled preference.

Unmindful

Answer 2

Hello To show firefox browser console log when the console is not showing in console log window please follow the below procedures

https://firefox-source-docs.mozilla.org/devtools-user/browser_console/index.html

NB: The Browser Console command line (to execute JavaScript expressions) is disabled by default. To enable it set the devtools.chrome.enabled preference to true in about:config, or set the “Enable browser chrome and add-on debugging toolboxes” (Firefox 40 and later) option in the developer tool settings.

Pizarro

As it’s currently written, your answer is unclear. Please edit to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers in the help center. – Mousebird