If the outbound rule is 'DENY', then change it to 'ALLOW'. Terms of Service | Privacy Statement © 2021 Cisco and/or affiliates. Otherwise, these processes are very simple and will work efficiently to fix your certificate errors for all browser in all platforms like Windows, Android, etc. Here’s how to diagnose and fix the issue: Fix 1: Check your Windows HOSTS file - Make sure there’s no entry in the hosts file that maps the website’s address to localhost or an incorrect IP address like 127.