Avast : Connection not established Error

when we install AV on any system of my company i am getting one error.

settings → update – > Virus definition – > Connection not established.

Screenshot is attached.

Please guide me why this error i am facing .?

Moreover if any port need to be open please let me know.

Urgent support required

You need to deploy updates through the console.
Make sure the client system(s) that you are trying to update are connected to the console.

Dear Due to this error “Connection not established” i am unable to see the client through console.