Hello, i fllied a ticked : https://github.com/pycom/pycom-micropython/issues/47 Testing with firmware 0.9.7 don't fix. I don't use garbage collector, and my code use only one thread. The error only occur after client connected in the message listen loop, and if i use the console. But server still running and working after error. I suspect interference with console or my own network because error occur only every 30 or 40 seconds Hope that it will be fixed by next Release ;-) Cheers