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Firefox won't open

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  • 1 has this problem
  • 17 views
  • Last reply by James

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Last night Firefox was running fine. I closed everything and left for a couple of hours. When I came back and opened Firefox everything was blank. There was a blank open tab, no response to any input in the address bar, nothing. So, I closed the window and tried again - this time it didn't even open. However, Task Manager showed Firefox running with 6-7 entries, all of which I used "End Task" on. I rebooted the computer and nothing had changed. It wouldn't open but it showed up a few times in Task Manager. I tried a Refresh - no change. I tried reinstalling - no change. I uninstalled and tried reinstalling - no change.

Finally, in desperation, I uninstalled, used "RegEdit" and deleted every entry I could that had "Firefox" in it. Then I reinstalled fresh - Firefix Installer didn't know it had ever been on my computer. Same result.

Honestly, I'm completely out of ideas. I can't try anything in Firefox because it won't open and I've deleted all the files and reinstalled and still no joy. Obviously, there is some file it's trying to use that is corrupted or something that isn't just a part of Firefox.

Any suggestions???

Last night Firefox was running fine. I closed everything and left for a couple of hours. When I came back and opened Firefox everything was blank. There was a blank open tab, no response to any input in the address bar, nothing. So, I closed the window and tried again - this time it didn't even open. However, Task Manager showed Firefox running with 6-7 entries, all of which I used "End Task" on. I rebooted the computer and nothing had changed. It wouldn't open but it showed up a few times in Task Manager. I tried a Refresh - no change. I tried reinstalling - no change. I uninstalled and tried reinstalling - no change. Finally, in desperation, I uninstalled, used "RegEdit" and deleted every entry I could that had "Firefox" in it. Then I reinstalled fresh - Firefix Installer didn't know it had ever been on my computer. Same result. Honestly, I'm completely out of ideas. I can't try anything in Firefox because it won't open and I've deleted all the files and reinstalled and still no joy. Obviously, there is some file it's trying to use that is corrupted or something that isn't just a part of Firefox. Any suggestions???

Chosen solution

Sorry to hear about this problem. By any chance, do you run Webroot security software?

There is an incompatibility between Webroot and 64-bit Firefox 97 with a recent Windows 10-11 update. People are working with Webroot to issue an update.

Until then, a user posted that one workaround is to run Firefox 97 in backwards compatibility mode. I haven't tested this myself, but here is how you would set that up:

(1) Open the Properties dialog for your Firefox shortcut. Either:

  • right-click a Desktop shortcut, then click Properties
  • right-click a pinned Taskbar icon, then right-click the Firefox (or Mozilla Firefox) item, then click Properties

(2) Switch to the Compatibility tab

(3) Check the box for "Run this program in compatibility mode for"

(4) If the selector for that option is not set on Windows 8, switch it to Windows 8

As a result of this change, you may notice that some Windows 10-specific features and styling are disabled. However, I am not aware of any major changes. If you experiment with this, let us know your experience.

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Seçilmiş Həll

Sorry to hear about this problem. By any chance, do you run Webroot security software?

There is an incompatibility between Webroot and 64-bit Firefox 97 with a recent Windows 10-11 update. People are working with Webroot to issue an update.

Until then, a user posted that one workaround is to run Firefox 97 in backwards compatibility mode. I haven't tested this myself, but here is how you would set that up:

(1) Open the Properties dialog for your Firefox shortcut. Either:

  • right-click a Desktop shortcut, then click Properties
  • right-click a pinned Taskbar icon, then right-click the Firefox (or Mozilla Firefox) item, then click Properties

(2) Switch to the Compatibility tab

(3) Check the box for "Run this program in compatibility mode for"

(4) If the selector for that option is not set on Windows 8, switch it to Windows 8

As a result of this change, you may notice that some Windows 10-specific features and styling are disabled. However, I am not aware of any major changes. If you experiment with this, let us know your experience.

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That fixed it! Thanks!! Hope Mozilla and Webroot find a solution, soon.

PS Windows build 19042.1526 I don't know when the last Windows update was but I can tell you, if it updated while I was away from the computer (when things went sideways), it didn't have to reboot because I was still logged into Windows. Firefox could have updated without me knowing but if it did, again, I had no indication of such though the browser was not open while I was AFK.


Now, if I can just get the space settings for the drop-down bookmarks back to where I had them I'll be almost back to normal!->

Modified by CoolNQuiet

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Chrome.css customization still works for menu spacing - now I'm happy!!

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https://www.mozilla.org/firefox/97.0.1/releasenotes/

Fixed Works around problems with WebRoot SecureAnywhere antivirus rendering Firefox unusable in some situations