Hello,
I think it is a failure in the USB connection between the Beaglebone and the host PC. One thing you might try is putting independent power into the beasglebone (it has a port for this); if the beaglebone is doing a lot of calculations it MIGHT draw too much power over USB and crash, so supplying independent power would fix this. Try that first, as well as getting a new USB cord (as short as possible) to link two.
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