Yes, I'm sure there isn't a physical short.
The error appears whenever M572 D0 S0.1 is sent through web control, slicer, or config.g, and never appears otherwise. With pressure advance on, the extruder motor does not move at all through slicer gcode or web control, but other functions appear unimpeded.
I replaced all config files with a fresh set made from RepRap Configurator last night, and it's having the exact same issue. Really don't know what could be going wrong at this point.
The start g-code on my slicer (PE Slic3r) only has a home all and lift nozzle command, and my current config.g is listed below:
; Configuration file for Duet Maestro (firmware version 1.21)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool on Wed Sep 26 2018 02:00:02 GMT-0700 (Pacific Daylight Time)
; General preferences
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves
M555 P1 ; Set firmware compatibility to look like RepRapFirmare
; Network
M550 PEnder 3 ; Set machine name
M552 P0.0.0.0 S1 ; Enable network and acquire dynamic address via DHCP
M586 P0 S1 ; Enable HTTP
M586 P1 S0 ; Disable FTP
M586 P2 S0 ; Disable Telnet
; Drives
M569 P0 S0 ; Drive 0 goes backwards
M569 P1 S0 ; Drive 1 goes backwards
M569 P2 S1 ; Drive 2 goes forwards
M569 P3 S0 ; Drive 3 goes backwards
M92 X80 Y80 Z400 E93 ; Set steps per mm
M566 X600 Y600 Z24 E300 ; Set maximum instantaneous speed changes (mm/min)
M203 X12000 Y12000 Z600 E1500 ; Set maximum speeds (mm/min)
M201 X2000 Y2000 Z250 E5000 ; Set accelerations (mm/s^2)
M906 X800 Y800 Z800 E800 I30 ; Set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout
; Axis Limits
M208 X0 Y0 Z0 S1 ; Set axis minima
M208 X230 Y240 Z250 S0 ; Set axis maxima
; Endstops
M574 X1 Y1 S1 ; Set active high endstops
; Z-Probe
M558 P0 H5 F120 T6000 ; Disable Z probe but set dive height, probe speed and travel speed
M557 X15:215 Y15:225 S20 ; Define mesh grid
; Heaters
M307 H0 B0 S1.00 ; Disable bang-bang mode for the bed heater and set PWM limit
M305 P0 T100000 B3950 C0 R2200 ; Set thermistor + ADC parameters for heater 0
M143 H0 S120 ; Set temperature limit for heater 0 to 120C
M305 P1 T100000 B3950 C0 R2200 ; Set thermistor + ADC parameters for heater 1
M143 H1 S280 ; Set temperature limit for heater 1 to 280C
; Fans
M106 P0 S1 I0 F500 H1 T45 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned on
M106 P1 S1 I0 F500 H-1 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P2 S1 I0 F500 H-1 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned off
; Tools
M563 P0 D0 H1 ; Define tool 0
G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets
G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C
; Automatic saving after power loss is not enabled
; Custom settings are not configured
; Miscellaneous
T0 ; Select first tool