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Returning to Firefox browser from other windows shrinks Firefox

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  • Last reply by FredMcD

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This is driving me crazy. When I have Firefox open in full screen with several tabs open, and then I go to another program window to do something and then come back to Firefox by clicking on the taskbar and selecting one of my Firefox tabs, the entire Firefox window, which had been full screen, shrinks to a smaller size. I really want it to stay full screen. Why does it do this? I have searched and searched and tried different things (safe mode, turning off all my add-ons, etc.) and nothing changes this behavior. What is going on? The only way to get it to remain full size is if I have the presence of mind to minimize the other windows, rather than select Firefox from the taskbar.

This is driving me crazy. When I have Firefox open in full screen with several tabs open, and then I go to another program window to do something and then come back to Firefox by clicking on the taskbar and selecting one of my Firefox tabs, the entire Firefox window, which had been full screen, shrinks to a smaller size. I really want it to stay full screen. Why does it do this? I have searched and searched and tried different things (safe mode, turning off all my add-ons, etc.) and nothing changes this behavior. What is going on? The only way to get it to remain full size is if I have the presence of mind to minimize the other windows, rather than select Firefox from the taskbar.

Chosen solution

Try this first; You may have a corrupt xulstore.json file.

Type about:support in the address bar and press enter.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Locate the xulstore.json file. Then rename or delete it. Restart Firefox.

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Chosen Solution

Try this first; You may have a corrupt xulstore.json file.

Type about:support in the address bar and press enter.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Locate the xulstore.json file. Then rename or delete it. Restart Firefox.

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Just to follow up that this does indeed solve the problem, thank you! I think some of the programs on my computer mess with that file, so I occasionally have to remove it and restart, but it always fixes the problem. My sanity is saved!

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Glad to help. Safe Surfing.