Protected lisp file

[SLW210]

To answer the original question, I would never bother trying to crack it, just learn to code or ask on a forum for a new solution, which many times will be better anyway.

 

If source is unknown, I wouldn't even want to use it.

 

If it's so old the author cannot be located or is long gone, then most likely there is something else out there better or even something newer AutoCAD does.