I can connect to the extender on all my devices but there is no internet access at all, through Ethernet, or wifi. The lights on the extender are as follows:

Power: Solid Green

Powerline: No light

Ethernet: Solid green when connected to Mac mini

Wireless: flashing fast.

I tried moving the extender to other rooms to try and get the powerline LED on and working, but nothing prevailed. I have been looking on these forums and have tried resetting the extender and still nothing, I even tried to set the IP addresses manually and still I get the same error for ethernet and nothing loading through WiFi. I know its not my home router as the WiFi still works perfectly when I use that. The error message I get when using ethernet is either "The cable for Ethernet is connected, but your computer does not have an IP address" or "Ethernet has a self-assigned IP address and will not be able to connect to the Internet". The TP-link kit itself is quite old I think as my dad bought it a few years back now and on the box, it says it supports windows 8, I was unable to figure out the hardware version and the firmware version but on the bottom of the box it says the model is: TL-WPA4220KIT(UK) and it says "Ver: 1.2" if that means anything. Any help would be greatly appreciated because the WiFi signal in certain rooms really struggles so having this was a life saver :)