Don't install this update if you can possibly avoid it.
I've seen three previously stable machines of different configurations all fail to boot following it. Even start-up repair doesn't work neither does uninstall recent system updates, as it says there is a pending update action.
Only way I could restore my machine and other machines was by doing a system restore to before the update was turned on. No matter what else I did I couldn't manage to fix the issue.
There appear to be a lot of issues with various things since this update which was rolled out starting last week.