Listing CTB Files ?

Hi, I'm attempting to return a list of available CTB files, but
I keep returning an error which I don't understand. Any clarification would be great. The code is:
(defun getctb ()
(vlax-safearray->list
(vlax-variant-value
(vla-getplotstyletablenames
(vla-get-activelayout
(vla-get-activedocument
(vlax-get-acad-object)
)
)
)
)
)
)

and the error returned is:
Backtrace:
[0.57] (VL-BT)
[1.53] (*ERROR* "ActiveX Server returned an error: Invalid index")
[2.48] (_call-err-hook #<SUBR @01c393fc *ERROR*> "ActiveX Server returned an
error: Invalid index")
[3.42] (sys-error "ActiveX Server returned an error: Invalid index")
:ERROR-BREAK.37 nil
[4.34] (safearray-get-element #<safearray...> -1)
[5.28] (#<SUBR @01c3c104 safearray->list> #<safearray...>)
[6.24] (vlax-safearray->list #<safearray...>)
[7.19] (GETCTB)
[8.15] (#<SUBR @01c39244 -rts_top->)
[9.12] (#<SUBR @01cd2334 veval-str-body> "(getctb)" T #<FILE internal>)
:CALLBACK-ENTRY.6 CALLBACK-ENTRY)
:ARQ-SUBR-CALLBACK.3 (nil 0)

Thanks for any help
Peter

 

Peter

You may need to call vla-RefreshPlotDeviceInfo first on the active layout -

Peter

 

That seems to do it - Thanks Peter