I had this one spot in my design and the system stopped with an error every time around, except when it cut off on a literal tangent twice.
G02 X468.1353 Y273.1857 Z-8.0000 I-36726.9630 J1234.0951
G03 X467.3183 Y249.1190 Z-8.0000 R836226.179450
G02 X471.8497 Y263.7913 Z-8.0000 I2487.2178 J-760.1286
the R 836226.179450 is the line that made it die each time. The first time it did it, I patiently waited and waited, but I was able to go view the gcode to figure out what line because the router was still there. Thankfully the WebControl go to gcode # allowed the program resume right where it had stopped. This had to be done 5 times on this one drawing. What is the maximum radius the arduino gcode parser can handle?