For others who may be reading, I just wanted to mention I also got the files in use box when installing this update on Exchange 2016. I did follow all the normal steps that I always do of disabling AV, stopping and disabling backup services, rebooting, running the update in an elevated window, etc. but for whatever reason it said the Microsoft Exchange Active Directory Topology service was running even though it along with all the other Exchange services were changed to a disabled state at that point of the install and all the others were stopped. I opened the services window and manually stopped this one service and clicked retry and it completed successfully. I rebooted and all the services started with no issue. Besides this one hiccup it went smoothly. Thanks.