I am trying to use "vla-addleader", but keep receiving an error:

BAD ARGUMENT TYPE: VLA-OBJECT #<VARIANT 8197 ...>
I am using the following code:

Code:
    (vla-addleader spc VertVar
      (vla-addMText
    (vlax-3d-Point
      (polar pt2 0 (/ (getvar "TEXTSIZE") 2.0)))
    (- (caadr tBox) (caar tBox)) tStr)
      acLineWithArrow)
Where, spc is the space retrieved, VertVar is a variant, like this:

Code:
    (setq Verts (apply 'append (list pt1 pt2))
      VertVar (vlax-make-variant
            (vlax-safearray-fill
              (vlax-make-safearray
            vlax-vbdouble
            (cons 0 (1- (length Verts))))
              Verts)))
and "(- (caadr tBox) (caar tBox))" is a number (real)

and tStr is just a string.

I can't work out what is going wrong

Thanks for your time

Lee


EDIT: Just seen I missed a "spc" from the MTEXT expression