Error: bad argument type: lselsetp nil

[stusic]

I got a lisp from the Cadalyst site that will work great for me, but it doesn't run; I keep getting an error: "ADD-BLOCKS - Error: bad argument type: lselsetp nil"


I've attached the code if it will help in troubleshooting.

Thanks for any help!

[Opie]

Do you have any blocks in your drawing? A needed selection set is nil.