I dont have Calmotion
Just guessing here (but I have seen it elsewhere before).
Yes - you probably need .NC file extension (don't ask me why - some programs don't care).
The device probably does not like spaces in the file name - this is typical for older CNC compatibility.
Does your program have a percent sign to start?
Just for fun - try this program (it is proven good)
%
N2 L200
N3 G1 Y.35 F85.
N4 Y.220 F16.
N5 X6.25 F30.
N6 Y.35 F50.
N7 G0 X18.25 Y2.
N8 M05 M9
N9 M00
N10 M3 M8
N11 M17
N12 M30
N13 G00 G40 G49 G80 G90 G17
N14 M6 T9 (Slot Mill - 5/16 T Slot cutter)
N15 G59 X18.25 Y2. (Datums Y Back - X Left)
N16 S2300. M3 M8
N17 Z0. H9 (Tool Zero at Cut height)
N18 L201.1
N19 G0 G90 H0 Z.0
N20 E0 X-5. Y9.9
N21 M05 M9
N22 M30
%
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