Go to the Firefox 3 Bar Menu --> Help ? --> Troubleshooting Information Page and take a look in the Accessibility section if accessibility is set to "true" there. if yes, go to the Firefox 3 Bar Menu --> Options --> Privacy & Security panel and under Permissions un-check the setting to Prevent Accessibility Services from accessing your browser. https://www.howtogeek.com/333110/how-to-customize-firefox-quantum-and-remove-the-white-space-around-the-title-bar/ Here's a more comprehensive project which affects not only tabs but brings back the old "grid-style" options menu. https://github.com/axydavid/FirefoxUI/blob/master/README.md It isn't completely possible to use the Australis design with Firefox 57, but depending on what you want, you might be able to customize the UI to look more like the old one: This project: https://github.com/wilfredwee/photon-australis lets you have the old tab bar appearance back in Firefox 57. You can remove the space around the address bar by right-clicking on the spaces, and choosing "remove from toolbar". Note the Black Theme is just a Example and can be found in Customize. https://mozilla.github.io/extension-finder/ Will not suck after playing with it...Customize away. Update your Video Card Drivers Please let us know if this solved your issue or if need further assistance.