Short story is that the Pi and Arduino/ RAMPS stop talking to each other and everything halts mid print and does not recover. I used to have the same issue with Octoprint and this happens every once in a while with Astroprint as well now. At least with Astroprint the heaters would be turned off but the last 2 times this happened (overnight and again just now) heaters remained on full blast so I figured it was time to bring the issue up.
What I’m experiencing sounds a lot like the “failure when resend is requested” issue you may have seen in octoprint (issue 166).
Running a pretty recent version of Marlin across my own line of Cohesion 3D Printers.
Thanks,
Ray