This guide shows you how to create or update an access rule of the McAfee Firewall. If you have an app, webcam, or another device, you’ll have to perform these steps. First, the firewall prompts you to accept or refuse to access the internet. And the selection you make, the firewall creates a rule to remember the choice. So if an app does not have a rule, the firewall blocks the application to protect the computer. For that, look for the app that is being blocked which will help you answer how do I stop McAfee blocking firewall? Then select the app and click on Edit. Then change the type from default to open to all devices.