You might start by reading http://www.catb.org/~esr/faqs/smart-questions.html
Then you could expand your question:
- Is this happening just for one particular FAS file or all on your machine?
- What happens if you re-compile the program`?
- What are the error reports when compiling?
- What are the error reports when running the program?
- How does the behaviour differ from what you expected?
- What AutoCAD version was the program written for? What are you now running?
- Can you reproduce the problem with a fresh, minimal example program?
- How does the fas loading order differ from loading your stuff as .lsp ?
- is the problem repeatable on another computer?
etc.
