virus definitions download failed (forbidden)

I just tried to install Avast Security on my Mac laptop (OS 10.13)
I got the above message.
I quit my browser first and do not have any other antivirus program.
What am I doing wrong?

please send us support package that will contain all the logs - Help > Avast Technical Support > Generate Support Package

I am also getting this error. I tried to uninstall and on re-install It says that its forbidden.