Try

loImaging = CreateObject("gdpicturepro5.imaging")
loImaging.SetLicenseNumber ("0012345678910111213141516") &&Demo code version
...

Check http://www.gdpicture.com/samples/acquire_twain_image_visual_foxpro.html

>I'm new to UT so I'm not sure if this is the right place to ask this quastion
>
>I have downloaded a 30 day evaluation license for GdPicture Pro Imaging SDK
>
>They tell me This License Key must be used with the SetLicenseNumber() method of each object of the Toolkit.
>
>That's fine but I can't find the SDK or a setlicencenumber method anywhere
>
>I'm using VFP to drive a scanner
>