Firefox

If you wish to discuss problems or ask questions related to Firefox, please use the MozillaZine Forums. This Knowledge Base simply provides documentation.

Issues		FAQ
This list of the more frequently-encountered issues or problems with Firefox is organized by subject and may include links to MozillaZine forum topics and other external sources in addition to Knowledge Base articles. It is not a complete list of Firefox issues. If you don't find an answer below, you can browse all articles in the Category:Issues (Firefox), use the Knowledge Base Search function, or look through the official list of known issues found in the Firefox release notes. General Firefox will not start up Firefox fails to start because js3250.dll or other files are not found Error loading websites Problems printing web pages (more here) Firefox says my profile is in use or that it is "already running but is not responding" Firefox hangs, freezes or stops responding Firefox CPU usage Firefox crashes (an error occurs and Firefox closes) Reducing Firefox memory usage ("memory leak") Standard diagnostic steps when Firefox is no longer working properly Installation and updates Internet access is blocked by your firewall after updating Firefox Add-ons not working or unable to install themes or extensions - Unexpected installation error -203 after an update "Java Console is incompatible" message after updating Firefox Other Software Update problems, including ""Software Update Failed" and "AUS: Update XML File Malformed (200)" messages Unable to install themes or extensions Problematic extensions (including those that cause conflicts with other extensions or plugins) Problems uninstalling extensions and removing "*.xpi" or "ghost" entries from the Extensions list Your Linux distributor releases a patched Firefox but the Firefox website wants to force you to update Bookmarks and browsing history All my bookmarks are gone I can't save new bookmarks I can't export bookmarks to an HTML file When I try to restore a bookmark backup I get the error, Unable to process the backup file. Bookmarks and browsing history are not working, back/forward toolbar buttons are disabled User interface Clipboard (cut/copy/paste) not working Scrolling with arrow keys no longer works Find bar opens when typing in textbox Window shakes Resizing an oversized window or setting Firefox to allow resizing of popup windows Large gray bar or box below the status bar Unable to search or add new engines Toolbar changes lost or buttons missing including customizations reset on startup, missing back/forward buttons after Firefox 3 upgrade, and other localstore.rdf issues. Downloading opening or saving files Unable to save or download files Downloads not visible in Download Manager Download error: The associated helper application does not exist when trying to open certain files The Download Actions list is empty "Do this automatically" grayed-out or not remembered and other issues with file types and download actions Opening files using plugins Opening files from the Downloads window "Open File - Security Warning" on Windows, when launching saved downloads (more here). Other Firefox file-opening and download issues Problems with specific websites or web features Websites look wrong Images or animations do not load (or images look wrong) Quicktime symbol with a question mark replaces Flash content Video or audio does not play Background music does not play Unresponsive Script Warning Popups not blocked (Details here) How to disable bookmark this page popup Why "ALT" text image tooltips do not work in Firefox. (Details here) Privacy and security User name and password not remembered Firefox asks for a nonexistent master password Websites report cookies are disabled when they're not "SSL is disabled" message "Could not initialize the browser's security component" message. Other errors loading secure sites Links to local pages do not work "Access to the port number given has been disabled for security reasons." Other Jar:File not found error ("Firefox can't find the file at jar:file:///C:/Program Files/Mozilla Firefox/chrome/en-US.jar!...") "Windows cannot find ..." error message (or extra tab/window) when opening Internet shortcut or local HTML file Uninstalling breaks file type associations or icons "Failed to save the preferences file" error or changes to preferences not saved Determining whether Firefox problems are caused by issues related to plugins Use IE messages upon opening Firefox (malware issue) Firefox.exe always open in the Windows Task Manager and automatically loads on Windows boot up (malware issue) Addresses entered in IE open in Firefox XPCOM:EventReceiver is not responding message on system shutdown Deleting Firefox profile via Profile Manager removes non-Mozilla files See also Firefox FAQs		This list of frequently-asked questions (FAQs) about Firefox is organized by subject and may include links to MozillaZine forum topics and other sources in addition to Knowledge Base articles. If you don't find an answer below, open the Help Contents from the Firefox menu, use the Knowledge Base Search function, or browse all articles in the Category:Firefox. General How do I install Firefox? How do I completely uninstall Firefox? Can I have both Firefox 2 and Firefox 3 installed at the same time? What's new in Firefox 3? (more here) Where can I download Firefox 2 or older Firefox versions? How do I set Firefox (or another browser) as the default browser? How do I use or configure the Software Update feature to update Firefox? Can I uninstall Internet Explorer or can I make it more secure? How do I make Firefox dial (connect) automatically in Windows? How do I make MSN Messenger open links in Firefox? Bookmarks and browsing history Where are my bookmarks stored? How do I import bookmarks from a file, or from Internet Explorer, MSN Explorer, Opera, Netscape or Safari? How do I export bookmarks to a file? How do I back up and restore my Firefox bookmarks? Can I share bookmarks among multiple profiles or store them in a different location? (more here for Firefox 3). How do I use the "Live Bookmarks" feature in Firefox to add RSS feeds? How can I alphabetically sort or rearrange my list of bookmarks? How can I view my browsing history or sort it differently? Profiles Where is the Firefox profile folder and what does it contain? What is the Firefox Profile Manager and how do I access it? How do I create a new Firefox profile on Windows? How do I transfer profile data such as bookmarks and passwords to a new profile? How do I back up my profile? How do I move my Firefox profile folder to a different location? How do I open a new instance of Firefox with another profile? Internet search How do I use the Search Bar or add new search engines? How do I remove search engines I don't need? How do I resize the Search Bar? Extensions and themes Customizing Firefox with add-ons (extensions and themes) How do I install extensions? What are themes and how do I install a new theme? How do I update extensions and themes? How do I uninstall extensions and themes? Plugins What is a plugin? PluginDoc information and downloads Where can I test my plugins? How can I find out which plugins Firefox is detecting? How do I install Java or get it working? How do I get the Flash or Shockwave plugins working? How do I install or enable the Quicktime browser plugins on Windows? How do I install RealPlayer or Real Alternative ? How do I install or get the Windows Media Player plugin working? The ActiveX plugin doesn't work in Firefox 2 so how do I remove it? How can I fix problems with the Adobe Reader plugin or other PDF viewer? How can I fix other issues related to plugins? Privacy and security What are cookies and where are they stored? What is a master password and how do I set a master password or change the settings? How do I block objectionable content? How do I delete "autocomplete" entries from the Location Bar, the Search Bar and some form fields on web pages? How can I set security policies to restrict or disable certain security settings or limit what websites can do via JavaScript? How do I allow only certain sites to use JavaScript? What kind of encryption does Firefox use? Where can I see a list of Firefox vulnerabilities? What is that small golden lock icon at the bottom of the screen? Why does it sometimes have a red slash over it? Configuring and customizing Firefox Firefox menu Options/Preferences How do I edit my configuration files? What is the user.js file? What are the userChrome.css and userContent.css files? What is about:config and what do the about:config entries represent? How do I reset preferences to the Firefox default settings? How do I customize my Firefox toolbars? How do I disable the autocomplete dropdown? How do I enable inline autocomplete? Can I disable the Smart Location Bar ( "AwesomeBar") in Firefox 3 or get the old location bar behavior back? Other What is Firefox Safe Mode and how do I access it to restore default settings or diagnose problems? How do I restore the mail integration toolbar and menu items in Firefox 2 to get mail and send new messages? What is the Session Restore feature? How do I find the Firefox disk cache or change its location? What are the accessibility features of Firefox for disabled, blind or visually impaired users? See also Issues with Firefox