Fix slowness, crashing, error messages and other problems
Error messages: what they mean and how to fix
How to troubleshoot error messages on Firefox
In English
- What does "Your connection is not secure" mean?
- How to troubleshoot the error code "SEC_ERROR_UNKNOWN_ISSUER" on secure websites
- Troubleshoot the "Secure Connection Failed" error message
- How to troubleshoot time related errors on secure websites
- Warning Unresponsive script - What it means and how to fix it
- What do the SSLv3 error messages mean on Firefox?
- "This Connection is Untrusted" error message appears - What to do
- How to allow Java on trusted sites
- Fix "The bookmarks and history system will not be functional" error message
- Unable to access secure (HTTPS) sites in Firefox 43
- Warning Unresponsive plugin - What it means and how to fix it
- "Firefox is already running but is not responding" error message - How to fix it
- Firefox says it's just updated every time it starts - how to fix
- How to fix the Update Failed error message when updating Firefox
- How to run Firefox when your profile is missing or inaccessible