This article describes the issues that are fixed in the Update Rollup for Azure File Sync Agent that is dated January 2019. Additionally, this article contains installation instructions for the update.

Improvements and issues that are fixed

  • Files are not tiered after upgrading the Azure File Sync agent to version 4.x.

  • AfsUpdater.exe is now supported on Windows Server 2019.

  • Miscellaneous reliability improvements for sync.

Note Update rollups for Azure File Sync Agent are cumulative. This update includes all the improvements and fixes that were included in the previous cumulative update.

More information about this update rollup

  • This update is available for Windows Server 2012 R2, Windows Server 2016 and Windows Server 2019 installations that have Azure File Sync agent version or later installed.

  • The agent version of this update rollup is

  • A restart may be required if files are in use during the update rollup installation.

How to get and install this update rollup for the Azure File Sync Agent

Update rollups for the Azure File Sync Agent are available from Microsoft Update and by manual download.


  • If the Azure File Sync agent is not currently installed on a server, use the agent installation package on the Microsoft Download Center. The agent installation package on Microsoft Update and Microsoft Update Catalog is intended for agent upgrades only.

  • To update existing agent installations, run AfsUpdater.exe (located in the agent installation directory) or download and install the update from Microsoft Update or Microsoft Update Catalog.

Microsoft Update

To get and install an update package from Microsoft Update, follow these steps on a server that has Azure File Sync agent installed:

Server 2016 

  1. Click Start, and then click Settings.

  2. In Settings, click Update & security.

  3. In the Windows Update window, click Check online for updates from Microsoft Update.

  4. Verify the update rollup package is listed and then click Install now.

Server 2012 R2

  1. Click Start, and then click Control Panel.

  2. In Control Panel, double-click Windows Update.

  3. In the Windows Update window, click Check for updates.

  4. Click Important updates are available.

  5. Verify the update rollup package is selected, and then click Install.

Microsoft Update Catalog

Go to the following website to manually download the update rollup package from the Microsoft Update Catalog:

Update Rollup for Azure File Sync Agent: January 2019 (KB4481059)

To manually install the update package, run the following command from an elevated command prompt:

msiexec.exe /p packagename.msp REINSTALLMODE=OMUS REINSTALL=StorageSyncAgent,StorageSyncAgentAzureFileSync,StorageSyncAgentGuardFilter,StorageSyncAgentUpdater /qb /l*vx storagesyncagentupdate.log

For example, to install the Azure File Sync agent update for Server 2016, run the following command:

msiexec.exe /p StorageSyncAgent_WS2016_KB4481059.msp REINSTALLMODE=OMUS REINSTALL=StorageSyncAgent,StorageSyncAgentAzureFileSync,StorageSyncAgentGuardFilter,StorageSyncAgentUpdater /qb /l*vx storagesyncagentupdate.log

Microsoft Download Center

Go to the Microsoft Download Center to manually download the agent installation package for new agent installations.

Note: To perform a silent installation for new agent installations, follow the steps documented in KB4459986.

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