invalid procedure call or argument?

[nareth]

whenever i try to run a second instance of my App i get this error

mycode is:

Let App.Title = App.Title & " V" & App.Major & "." & App.Minor & "." & App.Revision
    Let Caption = App.Title
    
    If App.PrevInstance Then
        Call AppActivate(App.Title)
        Call Unload(Me)
        Exit Sub
    End If