When there are issues with the Bitdefender firewall, the users may not be able to activate or enable their firewall, especially on the Windows 10 Operating System. The issue is not related to Bitdefender, but a common error on Windows, the case of the missing Windows Service called Base Filtering Engine.
The primary use or feature of the Base Filtering Service is that the service has full control over the operation of the Windows Filtering Platform. It is a network traffic processing platform that allows the software to pair with the Windows networking stack and perform several functions like traffic shaping, filtering, and firewall.
BASE FILTERING ENGINE (BFE) SERVICE IS PRESENT ON THE SYSTEM
Fix BFE in the Registry.
Perform the steps above, and you will be able to enable the Bitdefender firewall on your Windows 10 computer.