how to allow in firefox viewing content site secure by X-Frame-Options like www.google.com
i add in (about:config) settings
browser.frames.enabled = true
and its worked for some time but now it's not working again
I find good solution not for firefox but for chrome:
plugin: Ignore X-Frame headers
René Houkema
I've created an add-in for Firefox which ignores all x-frame options, see https://addons.mozilla.org/en-US/firefox/addon/ignore-x-frame-options/
Btw, this this question is similar to Disable X-Frame-Option on client side
来源：https://stackoverflow.com/questions/29370978/load-denied-by-x-frame-options-allow-in-firefox