Missing Something..

I am using the attached LSP routine to delete a particular dynamic block from multiple layout tabs in a drawing. But I seem to be missing something. I keep getting this after the command finsihes:

; error: bad argument type: VLA-OBJECT nil

And can't seem to figure out why. I know it has something to do with the search during the lisp looking for dynamic blocks but don't know how to tell it to stop after it has found them all.

Any help would be great.

Thanks - 

Autocad 2012 all sp's