Difficulties opening or using a website in Firefox 100

Firefox Firefox Last updated: 06/06/2022 50% of users voted this helpful

You may find that some webpages do not work correctly in Firefox version 100. This is due to the website not updating to accommodate version numbers with three characters.

If this impacts a website that you use often, there is a temporary workaround:

Warning: Changing advanced preferences can affect Firefox's stability and security. This is recommended for advanced users only.

  1. Type about:config in the address bar and press EnterReturn.
    A warning page may appear. Click Accept the Risk and Continue to go to the about:config page.
  2. Search for the network.http.useragent.forceVersion preference.
  3. Select the Fx71aboutconfig-EditButton button next to the preference and set its value to 99.
  4. Select Fx71aboutconfig-Checkmark to save the change.
  5. Restart Firefox.

To help Mozilla identify the websites where this issue is occurring, it would be appreciated if you could complete this form.

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