I am coming up with an intermittant problem where the program stops running and it comes up with message "radius to end of arc differs from radius to start" I know the file is ok as I have already cut this file on the large machine. Why would this be coming up especially when I could run this file again and it wouldn't faulter. It also does it with other files as well
Some versions of Mach3 are more tolerant than others with regard to this intermittent problem (load the file first time,it fails - load it a second time and it is OK).
It is worth checking that you have the correct IJ Mode set in Config / General Config and perhaps as a general rule ensure that it is defined at the start of all your Gcode files with G90.1 or G91.1 as appropriate for the way in which arcs have been created in your CAD / CAM.
Tweakie.