I was able to get my hands on a different powerline adapter and switched it with the TP-Link Mini TL-PA411. My problem is solved. It seems like that the combination of TP-Link Mini TL-PA411 and...

WiFi works fine for me. I reinstalled/updated the newest firmware to both of my adapters even though the newest version was already installled (What the Powerline Utility shows is wrong for some...

You should use the Powerline Scan Utility (green user interface). It will show you the IP of your wifi adapter. Which you can use to connect to the web interface using your browser. You can find the...

Model : TL-WPA4220 Hardware Version : V1 Firmware Version : 1.3.0.2134-00_422091_160421_033 Setup: Router connected to TP-Link Mini TL-PA411 (Firmware 1.0.0.337-01-20120309). Hard drive connected to...