I’m trying to use custom DOM events to communicate between the main world and the isolated world for a page in a webextension in Firefox. When trying to access an event object property, I get an access denied error. Most of what follows is just context. I really want to know what a “restricted” object is rather than how to make it unrestricted.

I’m trying to use custom DOM events to communicate between the main world and the isolated world for a page in a webextension in Firefox. When trying to access an event object property, I get an access denied error. Most of what follows is just context. I really want to know what a “restricted” object is rather than how to make it unrestricted.