(Partially solved) An odd print error...

Last night, I started a decent-sized print (about 6 hours, maybe a little less). After observing the initial layer being printed, I decided to go to bed and let it finish printing overnight. I woke up to a partially completed print missing several layers and my printer was at its “end of print” idle position with a cool nozzle and bed. Some of the last printed layer’s infill was missing in a pattern that suggests that it wasn’t even printed yet, and the console showed “unknown command: l” and no other errors. The printer still displayed “printing” on the LCD screen.

I’m using a TAZ 5 with the Marlin 2015Q2 firmware.

EDIT: Turns out I had a material jam. That doesn’t tell me what the error was, but I guess it’s not that important judging by some of the other threads here.