Windows Defender and Firewall off/disabled; Avast firewall will not start.
Perform a repair of avast.
If that doesn’t solve it perform a clean installation.
I have the same issue. Tried turning Windows Firewall off to check it wasn’t an incompatibility but that made no difference. Two restarts also made no difference. Error message is “Unable to start firewall.” I also just upgraded to 11.1.2245.
Running repair worked.
How do I run repair? Where is it in Avast? I’m having the exact same problem.
Control Panel> Program and Features> Select Avast> Select Repair.
When done, reboot the system.