Mozilla Firefox Help

Since  Firefox version  52 was released March 7, 2017, installed  NPAPI plugins  have not been supported in Firefox, except for Adobe Flash Player. Some of the plugins that no longer load in Firefox, even though they may be installed on your computer, include Java, Microsoft Silverlight and Adobe Acrobat.  Fix Firefox Error Over the past few years, Firefox has implemented various Web APIs so that websites can do the same things they’ve always done without plugins, so you will most likely not notice any change to your browsing experience. Why did Firefox do this? The internet is full of websites that go beyond static pages, such as video, sound and games. While NPAPI plugins, especially Flash, have helped enable these interactive pages, they also make your browsing slower, less secure and more likely to crash. Over the past few years, Firefox has worked hard to build replacements for these plugins, these replacements are called Web APIs. Web APIs are designed to ...

Troubleshoot Mode  is a special Firefox mode that can be used to diagnose and fix problems. When you start Firefox in  Troubleshoot Mode , it temporarily disables add-ons (extensions and themes), turns off hardware acceleration and certain other features, and ignores some customizations ( see below  to learn more). Comparing Firefox's behavior in normal mode to its behavior in  Troubleshoot Mode  may help pinpoint the cause of the problem.  Fix Firefox Error How to start Firefox in  Troubleshoot Mode Click the menu button  , click  Help , select  Troubleshoot Mode…  and click  Restart  in the  Restart Firefox in Troubleshoot Mode?  dialog. Troubleshoot Mode   window You will have two options: Clicking the  Open  button will start Firefox with the default theme, your extensions will be disabled, and some other features and customizations will be turned off. These changes are temporary. When you leav...

Some users have experienced issues with the  Lockwise Password Manager  not saving usernames and passwords when updating from an older Firefox version. This is due to a migration from using  key3.db  (in older versions) to  key4.db  (in current versions) when the decryption key is not migrated properly. This article describes how to safely migrate your login data for the latest version of Firefox.  Fix Firefox Error Find and back up old profile data First, make sure that you still have the  key3.db  file in your affected profile and save a backup copy, as follows: Click the menu button  , click  Help  and select  Troubleshooting Information .  The  Troubleshooting Information  tab will open. Under the  Application Basics  section next to Profile  Folder , click  Open Folder .  Your profile folder will open. Find the  key3.db  file and save a backup copy to an easy...

Malware  is short for "Malicious Software". It is a term generally used for software installed on your computer that is designed to infiltrate or damage a computer system without the owner's informed consent. Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of. This article describes what common symptoms are and how to prevent malware from being installed and get rid of them.  Fix Firefox Error How do I know that my Firefox problem is a result of malware? Symptoms are various and depend on the malware but if you have one or several of these behaviors, you may have malware installed on your computer. Some ad popups display all the time , although you've blocked popups. For more information on blocking popups, see Pop-up blocker settings, exceptions and troubleshooting. Your searches are redirected to another site  in order to feed you content from that website and you are being disallowed from blocking t...