The most common reason for this issue is interference from a VPN or proxy, or security software (like Kaspersky, BitDefender, or Avast) that changes security certificates. Other possible reasons include incorrect network settings or using outdated or incompatible protocols. Now that you know the causes, lets discuss the solutions to fix this error.
1. Disable VPN or Proxy Connection (if applicable)
If your VPN or proxy is on, it can interfere with secure connections by adding extra encryption or using methods that might not work with Firefox. Turning off the VPN or proxy lets Firefox connect directly with the website, using the correct security steps, which often solves the issue.
1.1. Delete the VPN Client
1.2. Disable Proxy Server
2. Refresh Firefox Browser
Sometimes, restarting Firefox can fix ongoing problems. Refreshing the browser returns it to default settings while keeping important data like bookmarks. This process removes add-ons, custom settings, and cached data that might cause issues. By resetting to a clear state, it removes possible conflicts, leading to smoother and better performance.
3. Disable DNS over HTTPS Option
Turning off DNS over HTTPS (DoH) can sometimes fix problems in Firefox. DoH encrypts DNS queries for security, but it can conflict with VPNs, proxies, or security software. Disabling DoH lets Firefox use standard DNS, which might solve these conflicts and restore connections.
4. Create a New Firefox Profile
A corrupted profile can cause browser errors. Creating a new Firefox profile can fix this by avoiding damaged settings or extensions. This new profile uses default settings, helping you see if the problem is with your current profile. It’s an easy way to check profile issues without losing your data.
5. Uninstall 3rd Party Security Suite
Third-party security software can block or change certificates needed for secure sites. Removing the software stops this interference, letting your system connect directly and securely. This ensures your browser can work without issues caused by the security suite’s scanning.
