Idem here : my laptop is running Ubuntu-14.10, upgraded Sync to 2.0.105 yesterday! I'm trying to link my Nexus 4 (Android 5.1 LMY47O) with Sync 2.0.85.0 by scanning the QR code, but it times out, one way or another : linking from the laptop = timeout, linking from the phone = timeout! I tried via WIFI on the same network, the data network on my phone, even tethering over wifi, NADA! If I create an identity on the phone and try to share a folder from the laptop, the only thing I see via 'tcpdump' via WIFI is ARP request by the laptop, no response from the phone and the laptop list the peer as "Offline"...