OctoPrint 1.3.12 Lulzbot Taz 6 Won't Print

What is the problem?
Just upgraded to Octoprint 1.3.12 running on OctoPi 0.15.1 and using a Lulzbot Taz 6. I can connect to the printer but then I click print the progress bar shows -100% and nothing happens.

What did you already try to solve it?
Power cycle, reboot, sacrifice to the gods

Logs (octoprint.log, serial.log or output on terminal tab, browser error console ...)
Changing monitoring state from "Operational" to "Starting"
Send: N0 M110 N0125
Recv: ok N0 P15 B4
Changing monitoring state from "Starting" to "Printing"
Changing monitoring state from "Printing" to "Finishing"
Send: N1 M400
38
Recv: ok N1 P15 B4
Changing monitoring state from "Finishing" to "Operational"
Recv: T:24.72 /0.00 B:25.72 /0.00 @:0 B@:0
Recv: T:24.66 /0.00 B:25.92 /0.00 @:0 B@:0
Changing monitoring state from "Operational" to "Starting"
Send: N0 M110 N0125
Recv: ok N0 P15 B4
Changing monitoring state from "Starting" to "Printing"
Changing monitoring state from "Printing" to "Finishing"
Send: N1 M400
38
Recv: ok N1 P15 B4
Changing monitoring state from "Finishing" to "Operational"
Recv: T:24.69 /0.00 B:25.96 /0.00 @:0 B@:0
Recv: T:24.66 /0.00 B:25.68 /0.00 @:0 B@:0
Recv: T:24.69 /0.00 B:25.68 /0.00 @:0 B@:0
Recv: T:24.69 /0.00 B:25.75 /0.00 @:0 B@:0
Recv: T:24.62 /0.00 B:25.78 /0.00 @:0 B@:0
Recv: T:24.78 /0.00 B:25.72 /0.00 @:0 B@:0
Recv: T:24.75 /0.00 B:25.72 /0.00 @:0 B@:0
Recv: T:24.53 /0.00 B:25.85 /0.00 @:0 B@:0
Recv: T:24.69 /0.00 B:25.72 /0.00 @:0 B@:0
Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ...)
Pi 3B, OctoPrint 1.3.13 running on OctoPi 0.15.1 Lulzbot Taz 6 Mac using safari

Try the safe mode to rule out any plugin issues