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safemode

Use Firefox "Troubleshoot Mode" (known as "Safe Mode" in previous versions of Firefox) to diagnose and fix problems. Learn more.

'''Troubleshoot Mode''' is a special Firefox mode that can be used to diagnose and fix problems. (Troubleshoot Mode was known as ''Safe Mode'' in previous versions of Firefox.) 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 ([[#w_more-information-advanced-users|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. __TOC__ = How to start Firefox in {for fx88}Troubleshoot Mode{/for}{for not fx88}Safe Mode{/for} = [[T:safemode]] = Troubleshoot Mode window = ;[[Image:Fx89TroubleshootModeWin10]] You will have two options: * Clicking the {button 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 leave Troubleshoot Mode and start Firefox normally, your add-ons and other settings will return to the state they were in before you entered Troubleshoot Mode. *Clicking the {button Refresh Firefox} button will restore Firefox to its factory default state while saving your essential information. These changes are permanent. See [[Refresh Firefox - reset add-ons and settings]] for more information, before you choose this option. =Diagnosing problems in Troubleshoot Mode= After you start Firefox in Troubleshoot Mode, you'll want to test its behavior and see if the problem goes away. == The problem happens in Troubleshoot Mode == If the problem still happens in Troubleshoot Mode, it is not being caused by an extension or theme. Other possible causes include changes made to Firefox preference settings, which are not disabled in Troubleshoot Mode. See the following articles for solutions: *[[Troubleshoot and diagnose Firefox problems]] *[[Reset Firefox preferences to troubleshoot and fix problems]] == The problem does not happen in Troubleshoot Mode == If the problem does not happen in Troubleshoot Mode, the most likely cause is an extension, theme or hardware acceleration. See this article for solutions: *[[Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems]] = Exiting Troubleshoot Mode = # [[T:closeFirefox]] # Start Firefox as you normally would. #* If Firefox keeps starting in Troubleshoot Mode, see [[Firefox is stuck in Troubleshoot Mode]]. = More information (Advanced users) = In addition to disabling add-ons (extensions and themes) and turning off hardware acceleration, Firefox Troubleshoot Mode disables [https://hacks.mozilla.org/2021/05/introducing-firefox-new-site-isolation-security-architecture/ Site Isolation], the [https://hacks.mozilla.org/2017/02/a-crash-course-in-just-in-time-jit-compilers/ JavaScript Just-in-time (JIT) compiler] and ignores the optional userContent.css and userChrome.css files (if present). The xulstore.json file, which saves [[Changes to toolbars and window sizes are not saved|customizations to window sizes, toolbar settings and controls]], is also ignored; however, any changes stored in [[Configuration Editor for Firefox|modified preferences]] remain in effect. <!-- MZ credit --> <br/> <br/> '''''Based on information from [http://kb.mozillazine.org/Safe_Mode Safe mode (mozillaZine KB)]''''' Share this article: mzl.la/firefox-troubleshoot