macquarie prime not accepting buy for cif

Tried to buy some CIF via Macquarie Prime today and was refused ...

Got this message ..

Macquarie Prime's credit and risk management teams assign a maximum exposure limit on stocks that Macquarie Prime offers lending over. This rigorous risk management process may mean that from time to time Macquarie Prime may be unable to accept new buy orders where a maximum exposure limit has been reached. These maximum exposure limits and margin rates are reviewed frequently but both the credit and risk management teams. We have been advised that Macquarie Prime has reached the maximum exposure limit assigned to CIF and we are therefore unable to accept new orders buy orders for CIF at this time.