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Firefox won't open in full screen

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When I close firefox while it's in full screen, turn off my laptop, and then open it again the day after, it opens in the small screen for some reason. I tried going to the root directory in the about:profiles section of the more troubleshooting information section and renaming xulstore.json to xulstore.json.old, and each time it worked for a few days and then it just installed a new xulstore.json and went back to opening in the small screen. This is really annoying and I don't want to switch it manually every time.

When I close firefox while it's in full screen, turn off my laptop, and then open it again the day after, it opens in the small screen for some reason. I tried going to the root directory in the about:profiles section of the more troubleshooting information section and renaming xulstore.json to xulstore.json.old, and each time it worked for a few days and then it just installed a new xulstore.json and went back to opening in the small screen. This is really annoying and I don't want to switch it manually every time.

All Replies (3)

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By "full screen" do you mean the window is maximized or actual full screen mode (F11)?

Make sure privacy.resistFingerprinting is false in about:config as this will force new windows to be unmaximized.

Does it still happen with all your extensions disabled?

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Use one of these to close Firefox if you are currently doing that by clicking the close X on the Firefox Title bar, especially if you have multiple windows or Private Browsing windows open to prevent losing tabs in unnoticed windows.

  • "3-bar" menu button -> Exit (Power button)
  • Windows: File -> Exit
  • Mac: Firefox -> Quit Firefox
  • Linux: File -> Quit
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zeroknight said

By "full screen" do you mean the window is maximized or actual full screen mode (F11)? Make sure privacy.resistFingerprinting is false in about:config as this will force new windows to be unmaximized. Does it still happen with all your extensions disabled?

I mean that it is maximised, not like with F11. I checked, and privacy.resistFingerprinting is false. I turned off my extensions so I guess I'll see if it goes back to opening in small screen in a few days or not.