Hope you enjoyed your Christmas if you celebrated one.

We will need a few more details, especially in regards to modem/router brand & model, ISP, etc.: System details - help us to help you (click on blue link)
Most likely the firewall detected was the NAT protection inside your modem/router. It suggests your router does not utilise UPnP for LW to communicate with the device to open a port. But we will know more when you post your details.

In meantime, try these suggestions & combine them: If LW Will Not Connect (click on the blue link)