Same problem here... first few small test prints with the new version worked fine and then it happened.
After power cyling the printer I could not even reconnect to it...
Went back to 0.3.10 same thing.... seriously wtf guys... do some QA.
Update: well 0.3.10 decided to connect again but still please test your software in house @proclaim
Recent software issues and the firmware bricking issue make me very hesitant now to even try new versions.