The requested address is not valid in its context when I try to listen a port

Use IPAddress.Any to listen. This seems to be your goal:

//listen on all local addresses

The listening address you have specified is invalid for some reason. There is no need to specify a numeric address.

The TcpListener listens for connections from TCP network client, on a given port on your local machine. That is, for incoming connections. Your code will be acting as a "server" of sorts.

The requested address is not valid in its context

Simply, it means that the IP address given is not used by any network interface on your machine.

Use IPAddress.Any to listen on any IP address (i.e. network interface).

However, it might be the case that you need to connect to the sensor (on port 3000), not the other way around.

EDIT: The new exception just tells you that you have two applications trying to listen to the same interface/port combination. Do you have two instances running at the same time?