Fix slowness, crashing, error messages and other problems
Fix problems with websites (Facebook, YouTube, webmail etc.)
How to troubleshoot security 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.
Configure firewalls so that Firefox can access the Internet
A firewall controls what programs can access the Internet. Find information about configuring your firewall to allow Firefox access to the Internet.
Firefox can't load websites but other browsers can
We'll explain errors such as "Server not found" or "Unable to connect" and how to fix problems where Firefox can't access websites but other browsers can.
Firefox tab crashes with Quick Heal security software
After the update to Firefox 63, some users with Quick Heal security software might be impacted by tabs repeatedly crashing. This article explains how to fix that.
Fix problems with Facebook games, chat and more
This article describes how to troubleshoot problems, like those with games or chat, that you might encounter while using Facebook in Firefox.
Websites look wrong or appear differently than they should
This article explains how to fix problems where a website doesn't look like it normally does or does not load correctly.
Firefox and other browsers can't load websites
If no web browsers on your computer can load websites, it indicates a problem with your Internet connection. The article describes some troubleshooting methods.
Fix problems connecting to websites after updating Firefox
Learn to troubleshoot and fix problems connecting to websites that start immediately after updating to a new version of Firefox.
Unable to log in to websites that use signText on Firefox
How to resolve login issues if your bank still uses a non-standard digital certificate (SignText) that Firefox no longer supports.
How to troubleshoot time related errors on secure websites
Learn why you might see time-related errors on HTTPS websites and how you can troubleshoot these errors by correcting your system clock.
Fix login issues on websites that require a username and password
If you find that you can't log in to a website that requires a username and password, follow the steps described in this article.
Websites don't load - troubleshoot and fix error messages
Are you having trouble getting a website to load? This article will show you how to fix the problem so you can get back to surfing the web.
Websites show a spinning wheel and never finish loading
Sometimes a website will start to load, but never finish. This article covers possible solutions.
Problems with email and how to find help
Find out the right direction to get help using webmail in Firefox and links to support pages for popular web-based email services.
