A simple form app has some parameters that are written to a text file on close.

Class FORM1
    private param1 as string
    public  paramset() as string   'Public because they are accessed in a child form
    ...

    sub Form_closing (sender As Object, e As CancelEventArgs) handles ME.Closing
         writeparamFile ()
    end sub
    
    private sub writeparamFile ()
        paramFile = New StreamWriter(thisProgramsPath & "X.ini")
        Using paramFile
              paramFile.WriteLine("param1=" & param1)
              paramFile.WriteLine("paramset=" & paramset(0) & "," & paramset(1) )
        end using...
    end sub

end class

While the first write-line works well and on debug PARAM1 has the correct value,
the array PARAMSET is set to NOTHING and writing generates a runtime exception.

Why is that? How do we get the array values at this stage of execution to record?