"No Function Definition” Error in AutoCAD LISP FIXED (100% Working)

In this video, I’ll show you how to fix the common “No Function Definition” error in AutoCAD LISP that suddenly appears even when your LISP file was working perfectly before. If you’ve ever loaded a LISP file and it stops working without any changes, this simple trick will help you solve the issue quickly. This problem is very common and can happen with many LISP files, not just one. I’ll guide you step-by-step on how to load the required Express Tools files and get your LISP working smoothly again. ✅ Quick and easy fix ✅ Works for multiple LISP files ✅ Beginner-friendly method