System.InvalidOperationException: Operazione non valida a causa dello stato corrente dell'oggetto.
   in System.Windows.Forms.DataGridView.DataGridViewDataConnection.ProcessListChanged(ListChangedEventArgs e)
   in System.Windows.Forms.DataGridView.DataGridViewDataConnection.currencyManager_ListChanged(Object sender, ListChangedEventArgs e)
   in System.Windows.Forms.CurrencyManager.OnListChanged(ListChangedEventArgs e)
   in System.Windows.Forms.CurrencyManager.List_ListChanged(Object sender, ListChangedEventArgs e)
   in System.ComponentModel.BindingList`1.OnListChanged(ListChangedEventArgs e)
   in Brini.GPD.Operatori.Attivita.AttivitaCollection.OnListChanged(ListChangedEventArgs e)
in C:\Lavoro\AttivitaCollection.vb:riga 94