The script was updated and you might not have the current version. You can install the latest one from the following page: https://goggles.mozilla.org/ Now... there still may be some sites on which X-ray Goggles don't work if those sites have a "Content Security Policy" forbidding Firefox from running code added to their pages from sources they haven't pre-approved. This generates an error message in the Browser Console (Ctrl+Shift+j) so if you find a page that seems immune to X-ray Goggles, you can open the console, click the Clear button to declutter it, then try X-ray Googles in the page. If there's a new line in the console with a red X mentioning Content Security Policy, then it won't work on that site.