Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox extends its vertical size each time it is started

  • 6 cavab
  • 1 has this problem
  • 11 views
  • Last reply by FredMcD

more options

This glitch happens since I've started using Firefox several years ago: every time I start Firefox it extends its vertical size by adding some pixels to its top and bottom.

How can I stop it? Restore xulstore.json each time I want to restore the FF window size doesn't look like a good idea.

Attached are screenshots of xulstore.json (colored is the current and black is the backup ones) to show the glitch clearly.

I'm currently using Windows 10 Pro.

This glitch happens since I've started using Firefox several years ago: every time I start Firefox it extends its vertical size by adding some pixels to its top and bottom. How can I stop it? Restore xulstore.json each time I want to restore the FF window size doesn't look like a good idea. Attached are screenshots of xulstore.json (colored is the current and black is the backup ones) to show the glitch clearly. I'm currently using Windows 10 Pro.
Attached screenshots

All Replies (6)

more options

https://support.mozilla.org/en-US/kb/changes-toolbars-and-window-sizes-are-not-saved You may have corrupt xulstore.json file.

Close Firefox. Open your file browser to this hidden location:

  • Mac: *~/Library/Application Support/Firefox/Profiles
  • Linux: *~/.mozilla/firefox/Profiles
  • Windows: %AppData%\Mozilla\Firefox\Profiles
  • *C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles
  • Windows XP: C:\Documents and Settings\<user>\Application Data \Mozilla\Firefox\Profiles\

Search for the above file. Then rename or delete it. Restart Firefox.

more options

Modified by kacharava.yuri

more options

FredMcD said

You may have corrupt xulstore.json file.

No, I may not. Deleted this file several times, recreated it by Firefox. Still increases its window's vertical size.

more options

Use these links to create a new profile. Use this new profile as is. Is the problem still there?

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

http://kb.mozillazine.org/Profile_folder_-_Firefox#Navigating_to_the_profile_folder

https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles


Type about:profiles<enter> in the address bar.

more options

FredMcD said

Use these links to create a new profile. Use this new profile as is. Is the problem still there?

Yes, it is.

more options

I called for more help.