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

Error Message

  • 4 replies
  • 1 has this problem
  • 1 view
  • Paskiausią atsakymą parašė aiwwe0897

more options

I am receiving the following message: Error: Platform Version 121.0 not compatible with minverssion >= 120.0.1

How do I fix?

I am receiving the following message: Error: Platform Version 121.0 not compatible with minverssion >= 120.0.1 How do I fix?

All Replies (4)

more options

Hello,mwburgess910

Certain Firefox problems can be solved by performing a Clean reinstall. This means you remove your Firefox program files and then reinstall Firefox. This process does not remove your Firefox profile data (such as bookmarks and passwords), since that information is stored in a different location.

To do a clean reinstall of Firefox, please follow these steps: Note: You might want to print these steps or view them in another browser.

  1. Download the latest Desktop version of Firefox from mozilla.org (or choose the download for your operating system and language from this page) and save the setup file to your computer.
  2. After the download finishes, close Firefox.
    • Windows: Click the Firefox menu Fx57Menu, then click "Exit".
    • Mac: Click the Firefox menu at the top of the screen, then click "Quit Firefox".
    • Linux: Click the Firefox menu Fx57Menu, then click "Quit".
  3. Delete the Firefox installation folder, which is located in one of these locations, by default:
    • Windows: (Note: Check both folders.)
      • C:\Program Files\Mozilla Firefox
      • C:\Program Files (x86)\Mozilla Firefox
    • Mac: Delete Firefox from the Applications folder.
    • Linux: If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it - see Install Firefox on Linux. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder firefox in your home directory.
  4. Now, go ahead and reinstall Firefox:
    1. Double-click the downloaded installation file and go through the steps of the installation wizard.
    2. Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.

More information about reinstalling Firefox can be found here.

WARNING: Do not use a third party uninstaller as part of this process. Doing so could permanently delete your Firefox profile data, including but not limited to, extensions, cache, cookies, bookmarks, personal settings and saved passwords. These cannot be easily recovered unless they have been backed up to an external device! See Back up and restore information in Firefox profiles.

Please report back to say if this helped you!

Thank you.

more options

The previous reply to your question looks like one created by AI.

It seems you have a mixture of old and new files. You need to remove the browser software completely and install anew. The problem may be caused by security software so you should disable that while reinstalling. You may want to consider a custom installation.

https://support.mozilla.org/en-US/kb/uninstall-firefox-from-your-computer https://support.mozilla.org/en-US/kb/custom-installation-firefox-on-windows

more options

Terry

The previous reply to your question looks like one created by AI. It seems you have a mixture of old and new files. You need to remove the browser software completely and install anew. The problem may be caused by security software so you should disable that while reinstalling. You may want to consider a custom installation. https://support.mozilla.org/en-US/kb/uninstall-firefox-from-your-computer https://support.mozilla.org/en-US/kb/custom-installation-firefox-on-windows

I'm not AI, please pay attention to what you said, thank you.

more options

aiwwe0897

Terry

The previous reply to your question looks like one created by AI. It seems you have a mixture of old and new files. You need to remove the browser software completely and install anew. The problem may be caused by security software so you should disable that while reinstalling. You may want to consider a custom installation. https://support.mozilla.org/en-US/kb/uninstall-firefox-from-your-computer https://support.mozilla.org/en-US/kb/custom-installation-firefox-on-windows

I'm not AI, please pay attention to what you said, thank you.

Top 22 Top 2

Maybe it's because I'm lazy and use the usual replies to answer like an AI, but it's provided by Mozilla, but I'm not an AI