Install this extension: https://addons.mozilla.org/en-US/firefox/addon/add-on-compatibility-reporter/ https://addons.mozilla.org/en-US/firefox/addon/add-on-comp

Install this extension: https://addons.mozilla.org/en-US/firefox/addon/add-on-compatibility-reporter/ https://addons.mozilla.org/en-US/firefox/addon/add-on-compat... And on the add-on screen you will be able to tell which addons are compatible with multiprocess and weather it is enabled or disabled. You may need to change a few extra things for multiprocess to work, like, accessibility features can block it from enabling. (my post is now a bit redundant since I didn't refresh it to look for any new comments)