Procedures to diagnose and fix problems
- How to troubleshoot the error code "SEC_ERROR_UNKNOWN_ISSUER" on secure websites This article explains why you might see the error code "SEC_ERROR_UNKNOWN_ISSUER" on HTTPS websites and how you can troubleshoot it.
- 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 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.
- 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.
- 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 Firefox issues using Safe Mode Firefox's Safe Mode is used for troubleshooting and fixing problems. Learn how to get into Safe Mode and what the various options do.