User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0 Build ID: 20170921100141 Steps to reproduce: For the first time in many years I had Firefox (FF57.0a1 64-bit) crash that crashes my computer. I was working on the Options page for my add-on and due to a typo error (got in an endless loop), not only hung the browser but also hung the operating system (Win7 64-bit). I don't know if the Option pages (and similar add-on related pages ie pop-ups, sidebar etc) are on a separate process but if they are not, I think they should be.