@GaryB you didn't write what kind of errors do you receive, but you should rethink the logic of your include statements. For example in your Sample3.AFL you only need to use: #include <Sample2.afl> because it already includes Sample1.afl
Sample3.AFL
#include <Sample2.afl>
Sample1.afl
https://www.amibroker.com/guide/afl/_include.html https://www.amibroker.com/guide/afl/_include_once.html
BTW - when pasting the code, use code tags. Read here: