Select() doesn't give control back. WaitForcontrol

Error: Operation timed out. (Exception From HRESULT: 0x80131505)

In WPF application, when i click on SelectionItem it will pop up a confirmation window. But when i use pattern.Select() on SelectionItem, i can see the popup but control cannot come back from pattern.Select() line. Error: Operation timed out. (Exception From HRESULT: 0x80131505)