If you're having website connection issues after a Firefox update, your third-party antivirus software, such as Avast, might be interfering with Firefox's secure connections.
We recommend uninstalling your third-party antivirus software and using the security software offered for Windows by Microsoft:
- Windows 8 and Windows 10 - Windows Defender (built-in)
For more information and other solutions, see How to troubleshoot security error codes on secure websites.
