The problem of the "NIL" error and nozzles not sorting as selected are results of the same problem: Some text files located in the VDP installation folder are improperly set to "Read Only" status. Consequently, VDP cannot make changes to these files to save setting changes, etc. The "NIL" error occurs when an attempt to write to these files is made.
Correct the problem by checking the file properties for file "vdpsetup.txt" located in the VDP folder. Uncheck the "Read only" setting if it is checked. Normally, VDP is installed into folder c:\Codeware\VDP.
There are several other text files in the same folder with "txt" file extensions. If similar problems occur with NIL errors or unsaved settings, then set these files also to allow them to be written to.
Tom Barsh
Codeware Technical Support