LookupGrid: Fix crash when clicking on new row checked column

Controls.LookupGrid/frmLookupGrid.vb

@@ -191,6 +191,11 @@ Public Class frmLookupGrid
     End Sub
 
     Private Sub viewLookup_RowCellClick(sender As Object, e As RowCellClickEventArgs) Handles viewLookup.RowCellClick
+        If e.RowHandle = GridControl.InvalidRowHandle Or e.RowHandle = GridControl.NewItemRowHandle Then
+            e.Handled = False
+            Exit Sub
+        End If
+
         ' When AllowFocus is used on the SELECTED Column, the checkbox can only be selected with a double click
         ' This function manually checks/unchecks the clicked cell
         If MultiSelect AndAlso e.Column.FieldName = COLUMN_SELECTED Then