Be aware that the update in Download Center applies to Microsoft Installer (.msi)-based edition of Office 2013. It does not apply to the Office 2013 Click-to-Run editions such as Microsoft Office 365 Home. (How to determine?).
Improvements and fixes
Fixes the following issues:
Office 2013 applications may crash because of an internal optimization task.
Because of the crash of the MSOSYNC.exe process that is part of being triggered by Windows Task Scheduler, Microsoft OneDrive for Business files sometimes cannot sync.
When the sync response that receives from the server is PathNotFound, the client should try for a configurable time, and then throttle for a configurable duration of time before retrying.
When you cannot upload or download files by using OneDrive for Business, you receive an inappropriate error message (for example, access denied).
Microsoft scanned this file for viruses by using the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to it.
You may have to restart the computer after you install this update.