Program won't load

Another problem in getting my DIY plasma cutter working.

I created a simple test program (2 circles) in an evaluation copy of Sheet-cam and when I try to load it in my licensed copy of Mach 3 I get a message saying Generating Tool Path and that's as far as it ever gets.

I've listed the program and a screenshot of Mach3 below and any help would be appreciated.

N0010 (Filename: 12 in circle.tap)
N0020 (Post processor: Mach3 plasma.scpost)
N0030 (Date: 09/03/2020)
N0040 G20 (Units: Inches)
N0050 G53 G90 G91.1 G40
N0060 F1
N0070 S500
N0080 (Part: 12 in circle)
N0090 (Operation: Inside Offset, LAYER_1, T1: Plasma, 0.0591 in kerf)
N0100 M06 T1 F3.937 (Plasma, 0.0591 in kerf)
N0110 G00 Z1.0000
N0120 X4.1256 Y9.9040
N0130 Z0.1181
N0140 M03
N0150 G04 P0.5
N0160 G01 Z0.0591 F3.937
N0170 G02 X4.0296 Y10.0000 I0.0000 J0.0960
N0180 X4.0296 Y10.0000 I5.9704 J-0.0000
N0190 M05
N0200 G00 Z1.0000
N0210 X11.7643 Y17.3153
N0220 Z0.1181
N0230 M03
N0240 G04 P0.5
N0250 G01 Z0.0591
N0260 G02 X11.6683 Y17.4113 I0.0000 J0.0960
N0270 X11.6683 Y17.4113 I1.4704 J0.0000
N0280 M05
N0290 G00 Z1.0000
N0300 M05 M30

and here is a screenshot of Mach3 and this ius far as it gets.

Attachment 438222