Procedures to diagnose and fix problems
- How to troubleshoot "Your connection is not secure" error codes on secure websites 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.
- Troubleshoot Firefox issues using Safe Mode To restart in Firefox Safe Mode to troubleshoot and fix problems, select "Restart with Add-ons Disabled" in Firefox's Help menu. Learn more.
- Troubleshoot Firefox issues caused by malware Malware is software designed to invade a computer without your knowledge. We'll explain common symptoms, how to prevent it being installed and how to remove it.
- Troubleshoot and diagnose Firefox problems Most issues with Firefox can be solved by working through these troubleshooting steps. Just start at the beginning and keep going until the problem is fixed.
- Reset Firefox preferences to troubleshoot and fix problems When troubleshooting Firefox problems, resetting user preferences can be helpful in pinpointing the issue. This article explains how to do it.
- Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems Follow these troubleshooting steps to determine if an extension, theme or hardware acceleration is the cause of a Firefox problem. Then get steps to repair.