@Dragonstone 

Hi, thanks for posting question on our community.

Internet light being off or the "WAN Port Unplugged" message means that your Router's WAN port physical connection is disconnected. It might be a problem of the Ethernet cable, or your modem, or the router itself, here are some instructions for you:

1. Make sure the Ethernet cable between the Router and the modem is tight. Try a different Ethernet cable if you have one.

2. Connect a PC directly into your modem to verify if your modem is working well.

3. Login the web management interface of the Router, go to Advanced > Network > Internet > Internet Port Negotiation Speed Setting > set to "100Mbps Full Duplex".

Still having issues? Please refer to this FAQ and  contact your local TP-Link support for further instructions.