Hi all, I. m facing similar problems. like you. I was working on upgrading my network to 2.1.1. I got stuck with strange behaviour of the GW. I programmed it with: IDE version: 1.8.4 Arduino AVR release: 1.6.20 The latest 2.1.1 downloaded libraries and the latest GW version. After connecting the GW to my network, i was perfectly able to ping it. MYScontroller could connect, however sending a command to the gateway rusults in an error (ERROR 10054). I've been fighting with it for a day, exchanging compontents, rebuilding SW, etc. Here is what solved it! Changed the AVR release to 1.6.11 I know there are problems in AVR 1.6.X, but these should have been solved in 1.6.18 and higher. Apperantly that is not the case. I hope this helps! Ralph