No and what does the Context Menu have to do with it and where are you talking about ? https://www.howtogeek.com/333110/how-to-customize-firefox-quantum-and-remove-the-white-space-around-the-title-bar/ and https://www.howtogeek.com/333805/how-to-change-or-customize-firefoxs-new-tab-page/ There is a reason why addons are not working is that they are incompatible if you are not finding them. https://www.howtogeek.com/333230/why-firefox-had-to-kill-your-favorite-extension/ If have not gone to the top of that page should do so as some words there to click on then it shows you old addons and a Blue Button to click. Or find a Alternative : https://addons.mozilla.org/en-US/firefox/extensions/ and start typing : https://mozilla.github.io/extension-finder/ If wanting to edit anything : https://www.howtogeek.com/334716/how-to-customize-firefoxs-user-interface-with-userchrome.css/ https://www.userchrome.org/ and https://www.userchrome.org/what-is-userchrome-css.html and https://github.com/axydavid/FirefoxUI/blob/master/README.md https://github.com/wilfredwee/photon-australis Will have to search as no code is in one place. There is a sub Reddit on this. https://support.mozilla.org/en-US/kb/update-firefox-latest-version Please let us know if this solved your issue or if need further assistance.