Screenshots should work on almost all web pages. Certain pages that contain the HTML <frameset> are not fully supported and may not be shootable.

Additionally, some pages with special permissions to modify Firefox, like Test Pilot and addons.mozilla.org, are unsupported due to strict security rules designed to prevent page manipulation.

Lastly, certain browser pages like the Firefox home and Options pages are not supported. These pages are built using a different language than the rest of the Web.

Please check, https://support.mozilla.org/en-US/kb/firefox-screenshots#w_why-doesnt-firefox-screenshots-work-on-certain-pages

I thought so too but it doesn't work at all and the icon next to it has disappeared.

Any problem reported in the Browser Console about the Firefox screenshot extension?

Nothing related to Firefox Screenshots.

Did you check this pref on the about:config page?

Can you take a screenshot with the developer tools version?

• https://developer.mozilla.org/en-US/Tools/Taking_screenshots

I already checked about:config and yes, I can take a screenshot with the Web Console.

Do you see the screenshot extension listed on the "Help -> Troubleshooting Information" (about:support) page under Firefox Features ?

This is a builtin system extension that is stored in the browser/features folder in the Firefox program folder. You can check the extensions.json file in the profile folder with the JSON viewer in a Firefox tab for more detail.

• https://developer.mozilla.org/en-US/Tools/JSON_viewer

You can use the search bar to find what number on the list this extension is. Then collapse all items and only expand this specific item.

Weird, I tried to set extensions.screenshots.disabled to true and back to false and now it works. Thank you all for the help.