Hi  @Pabery,

Is it your first time to set up range extender?

TP-Link range extender works with almost any Wi-Fi router and is easy to install. There are three ways to connect the TP-Link Range Extender to a router. Before you start, please power on the extender next to the router:

1. Via the WPS button, there is a physical WPS button on the Range Extender. Press the WPS button on the Router, and the Range Extender in turn. The Range Extender will connect to the Router automatically within 2 minutes. If the router doesn't have a WPS button, you may try the other two methods instead. For detailed instructions, please refer to:

Configure my Range Extender via WPS button

Alternatively, here is a full setup video for your reference:

How to set up a TP-Link Range Extender

  @Joseph-TP 
Hi Joseph, thanks for your support.
I have tried in every way, via the app and via the extender website but it cannot connect to the internet in any way.
As regards the first step, by connecting it near the modem, only the first two lights, power and wireless, come on steadily, while the 'RE' light remains flashing

Hi  @Pabery,

If you have tried all methods but still cannot configure, you can try to configure the range extender to other hotspots. If the problem still exists, it is most likely a hardware problem with the device. It is recommended that you contact local technical support to learn about warranty services.

If the problem disappears, it is recommended that you consult router support to confirm whether the limitation on the router caused the failure of configuration?

  @Pabery I am also facing this issue with a RouterBoard Mikrotik. The extender sees the Wifi Network, but it just doesn't want to connect. The extender works perfectly with other routers, but something must be preventing the extender from connecting to the Mikrotik router. Hopefully someone can help.