some ridiculous reasons you can't imagine that. my 186 DE (COOK) has been refused once in 2016 FEB. the reason is Immigration was chasing for the bank transition for the training fee. but we already mentioned training fee has been paid by cash and with full set of invoice and receipt. even we got 28 days to respond, and my MA told us this news at the last day, so we have to withdrawal the application and re-lodge again.