Lua: Error while running chunk
C:\Mach4Industrial\ScreenScript.lua:1380: attempt to index a nil value (global 'prb')
stack traceback:
   C:\Mach4Industrial\ScreenScript.lua:1380: in function 'btnSurfXHelp_Clicked_Script'

No error's when loading. just when you attempt to ask for help.

and if you attempt to probe
 
ESS: Mach4 Enabled
ERROR: Invalid probing G code