Performance and connectivity Deal with error messages, crashing applications, connectivity issues, and slow performance. Na Bekee Server Not Found - Troubleshoot connection problems Secure connection and security warning error pages in Firefox Troubleshoot time-related errors on secure websites Captive portal detection Fix "The bookmarks and history system will not be functional" error message Fix error “Website will not allow Firefox to display the page.” Use Troubleshoot Mode in Firefox Troubleshoot and diagnose Firefox problems Troubleshoot security error codes on secure websites Fix Firefox using too much memory or CPU resources Crash reports in Firefox for Android Task Manager - see whether tabs or extensions are slowing down Firefox Resist Fingerprinting How can I tell if Mozilla VPN is connected? Troubleshoot Mode Thunderbird How do I report a broken site in Firefox desktop? Warning Unresponsive script - What it means and how to fix it Rebuilding the Global Database Firefox DNS over HTTPS What do the security warning codes mean? Unload inactive tabs to save system memory in Firefox How Thunderbird for Android avoids leaking your IP address to SMTP servers DNS over HTTPS (DoH) FAQs Joining public WiFi while on Mozilla VPN How to let Firefox use the internet on your Windows computer Use the Troubleshooting Information page to help fix Firefox issues What is the Mozilla VPN kill switch? How to fix the Update Failed error message when updating Firefox Connecting to unsecured networks while using Mozilla VPN How do I report an issue with Firefox Relay? Websites look wrong or appear differently than they should Quick fixes if your Firefox slows down Mozilla Crash Reporter TB Where to go for developer support Unsent crash reports in Firefox "Firefox is already running but is not responding" error - How to fix Thunderbird makes unrequested connections How to reset the default user agent on Firefox Rate your Firefox experience, surveys and out of date messages (Heartbeat) How to obtain the Mozilla VPN Logs Crash reports in Firefox for iOS Firefox takes a long time to start up Some videos won't play in background Drag and Drop errors with Firefox Launcher Process enabled and Windows UAC disabled - How to Fix Report Site Issues on Firefox for iOS Compacting folders - Potential complications Solutions for "Can not create temp folder archive" error when installing Firefox (Windows 10) The language of the websites I visit changes when I turn Mozilla VPN on - What to do How to enable Always-on VPN on Android How can I help submit and resolve bugs in the MDN content repo? Where can I get help with the MDN API and documentation? Unsent crash reports in Firefox for Android Firefox hangs or is not responding - How to fix Firefox can't load websites but other browsers can Firefox uses too many CPU resources - How to fix Websites say that Firefox is outdated or incompatible even though it's the latest version Firefox says it's just updated every time it starts - how to fix Certificate contains the same serial number as another certificate Firefox does not work - Common fixes to get you back up and running How can I help by submitting mobile performance data? Memory constraints, Firefox performance and Firewalls Rebuilding Global Database How to resolve weak crypto error messages on Firefox Certificate warnings in Firefox for iOS 64-bit Firefox crashes with Citrix's XenApp VM Connection settings in Firefox Disable Firefox Sync Profiling Thunderbird Performance Firefox for iOS won't load web pages How to fix an error when trying to open Telegram or Slack on Firefox Fritz!box isn't working when Mozilla VPN is on Identify problems caused by third-party modules in Firefox for Windows Troubleshooting speed issues on Mozilla VPN Difficulties opening or using a website in Firefox 100 Difficulties opening or using a website in Firefox Focus for Android 100 How do I contact MDN Plus support? Why do I see a white screen after updating Mozilla VPN to version 2.8.3? Troubleshoot Mozilla VPN connection problems Firefox hangs when copying with Suggested Actions enabled on Windows 11 - What to do X-Mouse Button Control in Firefox 110 RCS messaging and Mozilla VPN Firefox blocked by macOS 15 Sequoia firewall - What you need to know Address screen sharing issues with Firefox on macOS 15 Sequoia HTTPS-First upgrades to secure connections Troubleshoot Firefox crashes (closing or quitting unexpectedly) Firefox is stuck in Troubleshoot Mode Firefox repeatedly opens empty tabs or windows after you click on a link Fix video and audio problems on Firefox for Windows N editions Avoid crashes - Tips and tricks Problems with email and how to find help Firefox keeps crashing at startup Home page with pipe character opens extra tabs when Firefox starts How to run Firefox when your profile is missing or inaccessible