Unblock Firefox from connecting to the Internet
- What does "Your connection is not secure" mean? When connecting to a website that uses an invalid TLS certificate or weak encryption, Firefox will display an error page saying "Your connection is not secure".
- How to troubleshoot the error code "SEC_ERROR_UNKNOWN_ISSUER" on secure websites This article explains why you might see the error code "SEC_ERROR_UNKNOWN_ISSUER" on HTTPS websites and how you can troubleshoot it.
- Configure Windows Firewall to allow Firefox access to the Internet A "Server not found" error can be caused by Windows Firewall blocking Firefox from accessing the Internet. Learn how to configure it to allow Firefox access.
- Unable to access secure (HTTPS) sites in Firefox 43 This article explains how to fix the error SEC_ERROR_CERT_SIGNATURE_ALGORITHM_DISABLED so you can access secure (HTTPS) sites in Firefox 43.
- Server Not Found - Troubleshoot connection problems If you can't connect to a website, you may see the Server Not Found error message. Learn how to troubleshoot and fix this error.