I have only been able to reproduce this on one screen. The screen is connected to a NVIDIA Quadro M1000M, with up to date drivers (v23.21.13.9103). The display that shows the problem is connected via DisplayPort to HDMI. The display not having issues is connected via DVI (using the internal Intel HD Graphics 530). I can reproduce this in both Firefox and Firefox Developer edition, both fresh installs with no plugins added. The way to repro is to maximize the browser on the screen with no issue, and witness no issue. Then drag the browser to the other screen and maximize the browser. What I see is intermittent behavior, but happens within the first 3-5 attempts to maximize. Maximizing on the other screen (which is using the internal Intel HD Graphics 530) shows no issue (fixes it again). You MUST maximize the browser on the 'working screen' first for this to occur. For example, if I follow these steps exactly, I can reproduce the problem: 1. Start browser 2. Drag browser window to 'working screen' (the never having problems screen) 3. Maximize the window. 4. Drag the window to the 'non-working screen' (meaning the one where everything else is perfectly fine except for firefox) 5. Maximize the window. (It will go completely black.) 6. To undo, drag the browser window back to the working screen, let go. 7. Drag the browser window back to the non-working screen, let go. 8. As long as you do not maximize it, it works fine. Interestingly enough, I cannot reproduce the problem while running either browsers in safe mode, but as I've said, these are fresh installs with no custom configuration or tools installed. As you can see in my attached screenshot, this is a screen capture of the browser sitting between both monitors, black on one side and normal on the other. If the browser is not maximized, it works flawlessly on both screens. As soon as you maximize it, it goes black and remains black until you drag it onto the other screen, let go, then drag it back. Good luck with that! It's pretty crazy.