XREF LAYER Error's

Recently i have been having issues with this lisp file. A close out of the drawing and opening it back up solves this problems. Which to me is really not a solution. I got this code from this forum just modified it for my use.

This is the error im getting.

Error: bad argument type: stringp (-1 . <Entity name: 7eb03b20>)

It's coming from this line of code.

(cons 2 (apply 'strcat (cdr b)))

I just don't know why. I'm sure its something easy.

Thanks.

(defun c:XREF_LAYER () ;( / a b c d lay_lst )
   (defun *Error* (Msg)
   (cond ((member Msg '("Function cancelled" "quit / exit abort")))
   ((princ (strcat "Error: " Msg))
   (princ "\nRestoring System Variables ")
   (terpri))) 
   (princ))
   (vl-load-com)
   (vlax-for lay (vla-get-Layers(vla-get-Activedocument (vlax-get-acad-object)))
       (if (= :vlax-true(vla-get-lock lay))
           (progn
               (vla-put-lock lay :vlax-false)
               (setq lay_lst (cons lay lay_lst))
           )
       )
   )
   (initget "ME-ANNO-XREF E-ANNO-XREF M-ANNO-XREF P-ANNO-XREF T-ANNO-XREF F-ANNO-XREF")
   (setq *layr*
     (cond
       (
         (getkword(strcat "\nChoose Layer [ME/M/E/P/T/F] <"(setq *layr*(cond ( *layr* ) ( "ME-ANNO-XREF" ))) ">: "))
       )
       ( *layr* )
     )
   )
   
   (while (setq a (tblnext "BLOCK" (null a)))
       (if (= 4 (logand 4 (cdr (assoc 70 a))))
           (setq b (cons "," (cons (cdr (assoc 2 a)) b)))
       )
   )
   (if (setq c
           (ssget "_X"
               (list
                   (cons 0 "INSERT")
                   (cons 2 (apply 'strcat (cdr b)))
                   (cons 8 (strcat "~" *layr*))
               )
           )
       )
       (repeat (setq d (sslength c))
           (entmod (list (cons -1 (ssname c (setq d (1- d)))) (cons 8 *layr*)))
       )
   )
   
   (if lay_lst(foreach l lay_lst(vla-put-lock l :vlax-true))(princ "No layers to restore"))
   (command "purge" "all" "" "n")
   (command "layer" "LO" *layr* "")    
   (princ)
)

Why have you commented the local variables?!?

Sorry i did that so i could see the variables when it was getting an error. Looks like i forgot to change it back. I do think i was getting the errors before this though. I will check, but i dont know what is actually make this error out in the drawing.

Are you sure that you have correctly identified the line on which the code throws an error? I say this because the error message doesn't seem to match the data held by that variable.

Did you follow this procedure to identify the source of the error?

I cant say that I'm 100% sure. When i got the error I went though each line of code via command line. this is the line that give me the error. I figured it could be something before not working right and sending the wrong variable to that line.

I did not follow that. first i have actually seen it. I will do so the next time i get the error.

One more thing. Thats awesome debugging LEE. Thanks.