Ncam "Insert G-Code File Command" using Buster - Error

Using Ncam's Insert G-Code File command in Buster, I am getting the error message in Axis as follows:

"nested subroutine definition."

Does anyone know how to solve this?

The g-code file....

o<cutoff> sub
G00 X3.175 Z-0.545
G02 X0 Z0 R9.525
G00 X31.75
o<cutoff> endsub
%

BTW....this works perfectly on my other computer running Debian Stretch.

Thank you,

Barry

Working on this problem I discovered something, but can anyone expand on why this is happening?
Maybe, LinuxCNC2.7.15 allowed sub routine nesting using o-codes but LinuxCNC2.8.1 does not?

Using NativeCAM embedded in LinuxCNC2.7.15, the G-Code file embedded within another subroutine worked perfectly; however, in LinuxCNC 2.8.1 the same G-code file gave the error "nested subroutine definition."

o<cutoff> sub
G00 X3.175 Z-0.545
G02 X0 Z0 R9.525
G00 X31.75
o<cutoff> endsub
%

To fix this in LinuxCNC 2.8.1, I had to remove the "sub" lines and the % at the end as shown below, and it worked.

G00 X3.175 Z-0.545
G02 X0 Z0 R9.525
G00 X31.75