Make sure you follow the below steps very carefully:
1. Download it.
2. If you downloaded the self-extracting file (.exe), then run it, otherwise, use your unzipping program to extract the files from the downloaded archive.
3. There should be 2 extracted files: NetworkActiv-PortImport-Console-xxx and NetworkActiv-PortImport-Daemon-xxx . The Console component is where you configure port forwards and is the component that needs to be on a computer that can be accessed (at least on one TCP port number) from the other computer. The Daemon component is the component that makes the connection to the Console component and is to be run on the computer that is behind the firewall/gateway/router.
4. Run the Console and make sure that the port is accessible from the other computer. This may require you to forward a TCP port in your router's configuration to the computer running the Console component.
5. If you are not going to use the default port already entered for the session (at the mid-top of the Console component's user-interface), then change it to the port you will be using.
6. Press the button titled Enable, located just to the right of the field for the session port.
7. Run the Daemon component (on the computer that is behind the router/gateway/firewall) and enter the hostname/IP-address from where the computer running the Console component can be accessed. If you are not using the default port number configured in the Daemon (in Settings->Advanced), then append a colon ( : ) to the hostname/IP-address, followed by the port number that you will be using for the PortImport session.
8. Press the Establish button on the Daemon component's user-interface. This will attempt to establish the PortImport session by connecting to port on the computer running the Console component configured as the session interface port. The status of the establishment can be seen just under the box where you entered the hostname/IP-address of the computer running the Console component.
9. If the Console component is not currently configured to automatically accept session-requests, you will need to manually accept the session by pressing the Accept button on the Console component's user-interface. Note that this button is only available when the Daemon has successfully connected to the Console and the Console has not yet accepted the session-request.
10. Once a session is established, you may proceed to create, edit, enable, and disable port forwarding operations (PFOs).