You need to run your headless Firefox with a new profile, otherwise you'll run into an error because you can't have two instances open with the same profile. To create a new profile, go to the about:profiles page in Firefox and use the Create a New Profile button.
Headless mode - Mozilla | MDN Headless mode is a very useful way to run Firefox. Just as it might sound, Firefox is run as normal, minus any visible UI components visible. Though not so useful for surfing the web, it comes into its own with automated testing. This article provides all you need to know about running headless Firefox. Multiple Firefox profiles - Mozilla | MDN If the Profile Manager window does not open, Firefox may have been running in the background, even though it was not visible. Close all instances of Firefox, or restart the computer, and then try again. If you want to do this frequently and more easily, you may wish … Firefox - Protect your life online with privacy-first Firefox is more than a browser. Learn more about Firefox products that handle your data with respect and are built for privacy anywhere you go online.
Jul 23, 2020
Firefox Not Open or Run - YouTube Oct 07, 2018 Firefox already running Issue - Ask Ubuntu Firefox 23.0 canonical 1.0 already running not shutting down or starting up error. States its already running need to shut-down do system restart and close browser.
Jul 23, 2020 · I was able to enable WebRender for both Linux and macOS versions of Firefox. On Windows 10, however, I was not.Even though about:config showed WebRender was enabled, about:support still listed the
If the Profile Manager window does not open, Firefox may have been running in the background, even though it was not visible. Close all instances of Firefox, or restart the computer, and then try again. If you want to do this frequently and more easily, you may wish … Firefox - Protect your life online with privacy-first Firefox is more than a browser. Learn more about Firefox products that handle your data with respect and are built for privacy anywhere you go online. Firefox 78.0.2 System Requirements Firefox will not run at all without the following libraries or packages: GTK+ 3.14 or higher; X.Org 1.0 or higher (1.7 or higher is recommended) libstdc++ 4.8.1 or higher; glibc 2.17 or higher; For optimal functionality, we recommend the following libraries or packages: NetworkManager 0.7 or higher; DBus 1.0 or higher; GNOME 2.16 or higher Firefox Beta - Internet for people, not profit — Mozilla