A Refresh can fix many issues by restoring Firefox to its default state while saving essential information like bookmarks and passwords.
Mozilla does not provide telephone support and does not charge for software downloads, upgrades or technical help. Learn more.
Learn about the error codes SEC_ERROR_UNKNOWN_ISSUER MOZILLA_PKIX_ERROR_MITM_DETECTED and ERROR_SELF_SIGNED_CERT on HTTPS websites and how to troubleshoot.
Some pages or page elements may fail to load after updating to Firefox 70. You can try a temporary workaround while we work on a fix.
Since the release of Firefox version 52 in March 2017, NPAPI plugins no longer load, except for Adobe Flash. Learn more about this change.
Firefox certificate pinning reports; what they are and why you might want to share yours.
Learn how to add an exception for Pocket in Firefox, to prevent being prompted to log in to Pocket when saving to the site.
There was a known issue in Firefox version 69 and Beta 70 that prevented you from downloading files in Windows 10 when parental controls were on.
You may be selected to rate Firefox or complete a survey. You may also see a notice to update Firefox. Learn more about these messages.
The Troubleshooting page has details such as installed extensions, preferences and graphics information, to help you solve Firefox problems.
There is a known issue with WindowBlinds and hardware acceleration that causes crashing in Firefox. Here are some workarounds you can try.
When accessing a site with SSLv3, Firefox will block it and display an "Unable to connect securely" message.
Learn why you might see time-related errors on HTTPS websites and how you can troubleshoot these errors by correcting your system clock.
How to enable Lastpass after updating to the latest version of Firefox.
Accessibility features are not yet fully supported in multiprocess Firefox. Restart Firefox to change it back to single process mode.
Some Windows accessibility tools might turn off Firefox's multi-process support. Here's how to re-enable it.
How to fix an issue that causes images and text to display as smeared or streaky lines or tears while scrolling before the update is available.
The API hooks from Citrix XenApp 7.13 VDA do not work with 64-bit Firefox. How to find a workaround.
Learn how to reset your Firefox "user agent" so that websites can detect your correct browser and version and display the way they should.
How to disable the Enterprise Roots preference to fix TLS connection errors caused by antivirus software, without compromising security.
If each open Firefox tab shows up in your Windows volume mixer, a fix will be released in Firefox version 76. Here is a workaround in the meantime.
Firefox Compatibility with Windows Exploit protection.
How to resolve the issue with Firefox asking for a master password if you have AVG or Eset Internet Security installed.
This page explains the error: "Website will not allow Firefox to display the page if another site has embedded it"
Firefox searches going to the wrong website can be caused by your Internet provider, an add-on, toolbar or malware. Learn how to fix this.
Learn how to troubleshoot and fix Firefox crashes, and find out how to get more help if you're having problems solving the issue.
This article covers a number of fixes you can try if this is happens to you.
This article describes why Firefox may start in Safe Mode when you expect it to start normally and how to fix the problem.
You can reset your Firefox master password if you've forgotten it. Careful: This will remove all of your saved usernames and passwords.
If Firefox has trouble playing video or music on a Windows computer, you can install the Media Feature Pack, if it's missing. Learn more.
Here are some easy things you can do to avoid crashes and keep Firefox running in tip-top shape.
Learn how to troubleshoot and fix printing problems in Firefox.
Find out the right direction to get help using webmail in Firefox and links to support pages for popular web-based email services.
If Firefox keeps crashing when you try to start it and other solutions don't work, a clean reinstall can often fix the problem.
Learn how to restore your home page if a third-party software vendor changes it so that their page always opens when you launch Firefox.
Submitting a bug for Sync? Please include these details.
Set up Firefox to open multiple home pages replacing the pipe character (|) with %7C.
This article shows you what to do if you cannot add new bookmarks or make other changes to your bookmarks.
How to fix the error ''Your Firefox profile cannot be loaded. It may be missing or inaccessible'' so that you can start and run Firefox.