Printer paused to reheat extruder and then crashed.  

Printer paused to reheat extruder and then crashed.

This was a fairly basic shape, 7-hour print, using the 0.20mm quality PLA profile (beefed up with extra bottom/top layers and perimeters), with Monoprice PLA+ filament.  I ran it a few days ago and came back and it had a big layer shift.  The part is positioned diagonally so it fits; the layer shift was exactly along the diagonal so I knew it wasn't a belt issue.   I tried again tonight and happened to be sitting here and noticed it stopped for a couple seconds, it was heating the extruder which was a couple degrees low. The first time it just picked up where it left off after couple seconds, no noticeable shift.   The second time it did the same thing but then immediately went off and crashed into the corner really hard so i turned it off right away.  I've been printing on the mk3 since November and never seen this before. 

I am running octoprint on raspberry pi zero which I know is problematic for some.  I am not using a camera so I haven't had any issues with it other the slow boot time.