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Firefox opens, but will not open websites. Cannot open settings. Cannot log in.

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Firefox 91.0.2 worked fine for several months.

Now it will open but when I enter a URL, it remains a blank white screen.

When I click on "Settings" it also remains a blank white screen.

When I click on "Sign In" it remains a blank white screen.

I have uninstalled and reinstalled. I have deleted my profile folder.

I like Firefox and would like to continue using it but it is currently not usable and I can't figure out how to make it usable again.

Firefox 91.0.2 worked fine for several months. Now it will open but when I enter a URL, it remains a blank white screen. When I click on "Settings" it also remains a blank white screen. When I click on "Sign In" it remains a blank white screen. I have uninstalled and reinstalled. I have deleted my profile folder. I like Firefox and would like to continue using it but it is currently not usable and I can't figure out how to make it usable again.

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Some problems occur when your Internet security program was set to trust the previous version of Firefox, but no longer recognizes your updated version as trusted. Now how to fix the problem: To allow Firefox to connect to the Internet again;

  • Make sure your Internet security software is up-to-date (i.e. you are running the latest version).
  • Remove Firefox from your program's list of trusted or recognized programs. For detailed instructions, see

Configure firewalls so that Firefox can access the Internet. {web link}

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Have you seen anything about this file being missing: VCRUNTIME140_1.DLL

When I had that problem, Firefox was pretty much blank from the tab bar down and unusable. If this problem started after installing or uninstalling some other software, you could download and reinstall the VCRuntime files from Microsoft here:

https://support.microsoft.com/en-us/topic/the-latest-supported-visual-c-downloads-2647da03-1eea-4433-9aff-95f26a218cc0

In the first section of the page, I installed both the 32-bit and the 64-bit, but I don't know if the 32-bit was really necessary. After the required reboot of Windows, Firefox was back to normal.