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Firefox opens itself as a mobile on my PC

  • 1 reply
  • 1 has this problem
  • 6 views
  • Last reply by cor-el

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Hello, Since today, after a new update, when I open Firefox, it displays as a mobile. As you can see on the picture it believes it is full screen. When I try to switch to full screen either by using the button or double clicking the top bar, it then just changes position across my screen, I have to do it again and only then it accepts to fit my windows, it's super annoying. I don't have any entry with useragent changed in my about:config. Thanks in advance.

Hello, Since today, after a new update, when I open Firefox, it displays as a mobile. As you can see on the picture it believes it is full screen. When I try to switch to full screen either by using the button or double clicking the top bar, it then just changes position across my screen, I have to do it again and only then it accepts to fit my windows, it's super annoying. I don't have any entry with useragent changed in my about:config. Thanks in advance.
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Try to rename/remove xulstore.json in the Firefox profile folder with Firefox closed.

You can use the button on the "Help -> More Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.