Hi,
when the Gcode interpreter gets a block of code it converts it all to lowercase, strips out leading zeros and any whitespace.
When Mach encounters:
M06 or
M 6
what it actually searches for is m6.
In most cases Windows is not case sensitive and therefore a search for m6 will return M6, but not always. Try renaming your macro to m6 not M6.
Next possibility is that there is a complied file somewhere; m6.mcc, That file will be returned even if you have a later m6.mcs. In the first instance go through your
Profile/Macros folder very closely deleting every m6 file you come across except the one m6.mcs you want to run. Now close Mach4 and restart so that the .mcs file
is complied and put into the screen script. Now try again.
Craig