As you confirmed you had your gw / sensors running on 2.x I gave it another try and started from scratch, and wiped the eeproms on both my gw and node. New Install of Arduino IDE, new MySensors Library install. I used the ethernet gw sketch example and a temperature sensor node sketch. This time it worked, I was able to finally include the sensor, what I can tell from the debug output communication seems to be working flawless. Even when cutting power from gw or sensor and powering up again communication is recovering. Now I will work on adapting my old sensor node sketch on lib 1.4 to new 2.1 requirements. Thank you so much for taking the time to help me get this going