@Frederick,

As Poison Byte said, you've to update to A7.05, then do one
of the followings :


1) In main.wdl write : PATH "C:\\Program Files\\GStudio7\\code";
and in main.c write : #include <mtlFX.c> OR,

2) Copy mtlFX.c into your work folder, and in main.c write :
#include "mtlFX.c"