This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

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 update failed, now browser will not function.

  • 4 replies
  • 0 have this problem
  • 1 view
  • Last reply by dsudduth

more options

Hello, Something strange happened during a recent Firefox update, not sure if it was something I did, or computer related, but now Firefox does not function. The browser will open but will not load any websites. Also, settings page will not open. If Firefox browser is closed and reopened a message is shown stating "Firefox is already running but is not responding. The old Firefox process must be closed to open a new window".

My troubleshooting actions: Installed/Uninstalled firefox several times, removed c:\ProgramData\Modzilla folder - status/functionality mentioned above does not change.

Windows running on target computer is completely updated and patched.

Thanks for assist, David

Hello, Something strange happened during a recent Firefox update, not sure if it was something I did, or computer related, but now Firefox does not function. The browser will open but will not load any websites. Also, settings page will not open. If Firefox browser is closed and reopened a message is shown stating "Firefox is already running but is not responding. The old Firefox process must be closed to open a new window". My troubleshooting actions: Installed/Uninstalled firefox several times, removed c:\ProgramData\Modzilla folder - status/functionality mentioned above does not change. Windows running on target computer is completely updated and patched. Thanks for assist, David

Chosen solution

Hi David, those crash report IDs seem to be missing some of their numbers.

Let me mention something else that often is relevant when Firefox seems to be dead from the address bar down:

Sometimes program installers and uninstallers mess with certain shared Microsoft files, particularly the VCRUNTIME140_1.DLL file. Firefox doesn't work properly without that file and you may or may not get a popup that the file is missing.

To rule out that issue, you can (re)run Microsoft's installer for the VC Runtime files:

(A) Open https://docs.microsoft.com/en-US/cpp/windows/latest-supported-vc-redist?view=msvc-160#visual-studio-2015-2017-2019-and-2022

(B) In the "Visual Studio 2015, 2017, 2019, and 2022" section of the article, download the installer for your system:

  • 64-bit Windows: the "X64" download
  • 32-bit Windows: the "X86" download

(C) Run that installer and restart Windows.

Any improvement?

Read this answer in context 👍 1

All Replies (4)

more options

We're sorry to hear that your Firefox seems to be crashing when you open it. Is this a copy of Firefox from the Microsoft store?

Please perform the following steps to give us a crash report ID that helps us find out more about the cause of the crash.

  1. On the keyboard, press [Windows] The image "Windows key" does not exist. + [R]. This should bring up a Run window that contains a text field.
  2. In that text field, type %APPDATA% and press Enter. An explorer window should open.
  3. From that explorer window, double-click on the Mozilla folder, then double-click on Firefox and then on Crash reports. Double-click on submitted.
  4. Now, you should see a list of files that contain reports. Go to View > Arrange Icons by > Modified to get the most recent files at the top of the window.
  5. Open the most recent 5 files with a text editor and copy the IDs.
  6. Paste each ID with bp- into the reply window on the forums.

Thanks in advance!

You can find more information and troubleshooting steps in the Troubleshoot Firefox crashes (closing or quitting unexpectedly) article.

more options

bp-1666279632 bp-1666277489 bp-1665770142 bp-1665172576 bp-1621283335

more options

Chosen Solution

Hi David, those crash report IDs seem to be missing some of their numbers.

Let me mention something else that often is relevant when Firefox seems to be dead from the address bar down:

Sometimes program installers and uninstallers mess with certain shared Microsoft files, particularly the VCRUNTIME140_1.DLL file. Firefox doesn't work properly without that file and you may or may not get a popup that the file is missing.

To rule out that issue, you can (re)run Microsoft's installer for the VC Runtime files:

(A) Open https://docs.microsoft.com/en-US/cpp/windows/latest-supported-vc-redist?view=msvc-160#visual-studio-2015-2017-2019-and-2022

(B) In the "Visual Studio 2015, 2017, 2019, and 2022" section of the article, download the installer for your system:

  • 64-bit Windows: the "X64" download
  • 32-bit Windows: the "X86" download

(C) Run that installer and restart Windows.

Any improvement?

more options

Hello, All good after VC Runtime files reinstalled.

Much thanks and appreciation for assist jscher2000 & Paul!