Exchange CU9 Upgrade Error

Hello,

I get the following error prior to the upgrade. Do you have information?

Error:
Setup can't continue with the upgrade because the monad (35812) has open files. Close the process, and then restart Setup.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.ProcessNeedsToBeClosedOnUpgrade.aspx

Thanks.