Partprograms.open scripting error

Found this in my repository...

Dim PCDApp, PCDPartPrograms, PCDPartProgram

Set PCDApp = CreateObject("PCDLRN.Application")
Set PCDPartPrograms = PCDApp.PartPrograms

PCDApp.Visible = True
PCDPartPrograms.Open "Z:\test1.PRG", "CMM1"

Set PCDPartProgram = PCDApp.ActivePartProgram

'msgbox "This will start the execution of the partprogram!"
PCDPartProgram.Execute

' PC-DMIS executes the partprogram

PCDPartProgram.Close

' PC-DMIS closes and saves the partprogram

PCDPartPrograms.Open "Z:\test2.PRG", "CMM1"

Set PCDPartProgram = PCDApp.ActivePartProgram

'msgbox "This will start the execution of the partprogram!"
PCDPartProgram.Execute

' PC-DMIS executes the partprogram

PCDPartProgram.Close

' PC-DMIS closes and saves the partprogram

' Cleanup
Set PCDPartProgram = nothing
Set PCDPartPrograms = nothing
Set PCDApp = nothing

This should (in theory) open "test1.prg", execute it, close and save and then open "test2.prg", execute it, close and save.