June 26, 2019—KB4509478 (OS Build 17134.860)
OS Build 17134.860
The Windows 10 April 2018 Update will reach end of service on November 12, 2019 for Home and Pro editions. We will begin updating devices running the Windows 10 April 2018 Update starting July 16, 2019 to help ensure that these devices remain in a serviced and secure state. For more information, see the Windows 10, version 1903 section of the release information dashboard.
Note Follow @WindowsUpdate to find out when new content is published to the release information dashboard.
Reminder: March 12 and April 9 will be the last two Delta updates for Windows 10, version 1803. Security and quality updates will continue to be available via the express and full cumulative update packages. For more information on this change please visit our blog.
Starting with update KB4499183, we are introducing functionality that allows you to decide when to install a feature update. You control when you get a feature update while simultaneously keeping your devices up to date. Feature updates that are available for eligible devices will appear in a separate module on the Windows Update page (Settings > Update & Security > Windows Update). If you would like to get an available update right away, select Download and install now. To find out more about this feature, please go to this blog.
When Windows 10 devices are at, or within several months of reaching, end of service, Windows Update will begin to automatically initiate a feature update. This keeps those devices supported and receiving the monthly updates that are critical to device security and ecosystem health.
Improvements and fixes
This update includes quality improvements. Key changes include:
Addresses an issue that may prevent devices from connecting to some Storage Area Network (SAN) devices using Internet Small Computer System Interface (iSCSI) after installing KB4499183. You may also receive an error in the System log section of Event Viewer with Event ID 43 from iScsiPrt and a description of “Target failed to respond in time for a login request.”
If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device.
Known issues in this update
Certain operations, such as rename, that you perform on files or folders that are on a Cluster Shared Volume (CSV) may fail with the error, “STATUS_BAD_IMPERSONATION_LEVEL (0xC00000A5)”. This occurs when you perform the operation on a CSV owner node from a process that doesn’t have administrator privilege.
Do one of the following:
Microsoft is working on a resolution and will provide an update in an upcoming release.
We are investigating reports that a small number of devices may startup to a black screen during the first logon after installing updates.
This issue is resolved in KB4519978.
Devices that start up using Preboot Execution Environment (PXE) images from Windows Deployment Services (WDS) or System Center Configuration Manager (SCCM) may fail to start with the error "Status: 0xc0000001, Info: A required device isn't connected or can't be accessed" after installing this update on a WDS server.
This issue is resolved in KB4512509.
How to get this update
Before installing this update
Microsoft strongly recommends you install the latest servicing stack update (SSU) for your operating system before installing the latest cumulative update (LCU). SSUs improve the reliability of the update process to mitigate potential issues while installing the LCU. For more information, see Servicing stack updates.
If you are using Windows Update, the latest SSU (KB4497398) will be offered to you automatically. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog.
Install this update
To download and install this update, go to Settings > Update & Security > Windows Update and select Check for updates.
To get the standalone package for this update, go to the Microsoft Update Catalog website.
For a list of the files that are provided in this update, download the file information for cumulative update 4509478.