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.
Reminder March 12 and April 9 were 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.
ePub support ending in Microsoft Edge
Microsoft Edge will end support for e-books that use the .epub file extension over the next several months. For more information, see Download an ePub app to keep reading e-books.
- Updates an issue that may cause a browser to stop working on certain architectures.
- Updates an issue that prevents Microsoft Narrator from opening.
- Updates an issue that doesn't provide a cursor when you select a text input box using touch.
- Updates an issue that causes excessive CPU usage when you switch applications or hover over the Taskbar.
Improvements and fixes
This non-security update includes quality improvements. Key changes include:
- Addresses an issue that may cause a browser to stop working on certain architectures.
- Addresses an issue that prevents Microsoft Narrator from opening when the User Account Controls setting is disabled on the Standard User account.
- Addresses an issue that fails to provide a cursor when you select a text input element using touch.
- Addresses an issue with configuring a lock screen image using a Group Policy. If you have enabled AppLocker DLL rules, the image does not change. Instead, you will get a solid blue background.
- Addresses an issue that causes excessive central processing unit (CPU) usage when users switch applications or hover over the Taskbar.
- Addresses an issue that prevents an App-V application from opening and displays a network failure error. This issue occurs under certain circumstances, such as when a system's battery is low or there is an unexpected power failure.
- Addresses an issue that may not preserve changes to the access control policy when upgrading to a newer version of Windows 10.
- Addresses an issue that may cause authentication to fail for certificate-based authentication when the certificate authentication includes a cname as part of the pre-authentication request.
- Addresses an issue that prevents a web browser from connecting securely to Windows Server. This occurs when using a client authentication certificate, such as a SHA512-based certificate, and the web browser does not support a signature algorithm that matches the certificate.
- Addresses an issue that may cause the Local Security Authority Subsystem Service (LSASS) to stop working with an “0xc0000005” error.
- Changes the default setting for BitLocker when encrypting a self-encrypting hard drive. Now, the default is to use software encryption for newly encrypted drives. For existing drives, the type of encryption will not change.
- Addresses an issue that prevents the BitLocker recovery key from being successfully backed up to Azure Active Directory.
- Addresses a possible compatibility issue when Microsoft Defender Advanced Threat Protection (ATP) accesses case-sensitive Server Message Block (SMB) shares.
- Addresses a rare issue that occurs when the mssecflt.sys driver takes too much space on the kernel stack. This results in the error, "STOP 0x7F: UNEXPECTED_KERNEL_MODE_TRAP", and Parameter 1 is set to “EXCEPTION_DOUBLE_FAULT.”
- Addresses an issue that leads to excessive memory utilization in Microsoft Defender Advanced Threat Protection (ATP).
- Improves the detection accuracy of Microsoft Defender ATP Threat & Vulnerability Management.
- Addresses an issue that gives a Windows Hello for Business user two certificates for authentication during certificate renewal instead of one certificate.
- Addresses an issue that causes the lsass.exe service to stop working, which causes the system to shut down. This occurs when migrating Data Protection API (DPAPI) credentials using dpapimig.exe with the -domain option.
- Addresses an issue that may give write access to a removable USB disk when a user switches from a privileged user to an unprivileged user.
- Addresses an issue that prevents you from running the Active Directory Diagnostics Data Collector Set from the Performance Monitor for Domain Controllers. This causes the Data Collector Set name to appear empty. Running the Active Directory Diagnostics Data Collector Set returns the error, “The system cannot find the file specified.” Event ID 1023 is logged with the source as Perflib and the following messages:
- “Windows cannot load the extensible counter DLL “C:\Windows\system32\ntdsperf.dll.”
- “The specified module could not be found.”
- Addresses an issue in GetFinalPathNameByHandleW() that prevents Favorites from opening in Internet Explorer 11. This occurs when Favorites are redirected and offline in a client-side caching scenario with enhanced protected mode compatibility (EPM) enabled.
- Addresses an issue with the Origin request header behavior in Internet Explorer when you make cross-origin resource sharing (CORS) requests that use redirected resources in internal subnets.
- Allows auditing of security events for clients managed by mobile device management (MDM) for security monitoring and incident response activities.
- Addresses an issue that causes virtual desktop infrastructure (VDI) environments to show black, flashing rectangles on the screen when using Microsoft Outlook and Microsoft Office.
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:
|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.
|After installing this update, Windows Mixed Reality Portal users may intermittently receive a “15-5” error code. In some cases, Windows Mixed Reality Portal may report that the headset is sleeping and pressing “Wake up” may appear to produce no action.|| |
This issue is resolved in KB4519978.
|Some Input Method Editor (IME) may become unresponsive or may have high CPU usage. Affected IMEs include Chinese Simplified (ChsIME.EXE) and Chinese Traditional (ChtIME.EXE) with Changjie/Quick keyboard.|| |
Due to security related changes in this update, this issue may occur when the Touch Keyboard and Handwriting Panel Service is not configured to its default startup type of Manual. To resolve the issue, perform the following steps:
The TabletInputService service is now in the default configuration and IME should work as expected.
|The print spooler service may intermittently have issues completing a print job and may result in a print job being canceled or failing. Some apps may close or generate errors when the print spooler fails and you may receive a remote procedure call error (RPC error) from some printing utility or printing apps.|| |
This issue is resolved in KB4524149.
When setting up a new Windows device during the Out of Box Experience (OOBE), you might be unable to create a local user when using Input Method Editor (IME). This issue might affect you if you are using the IME for Chinese, Japanese, or Korean languages.Note This issue does not affect using a Microsoft Account during OOBE.
To mitigate this issue, set the keyboard language to English during user creation or use a Microsoft Account to complete OOBE. You can set the keyboard language back to your preferred language after user creation. Once the OOBE is done and you are at the desktop, you can rename the current user using these instructions. If you prefer to create a new local user, see KB4026923.
Microsoft is working on a resolution and will provide an update in an upcoming release.
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.
Install this update
|Release Channel||Available||Next Step|
|Windows Update or Microsoft Update||Yes||Go to Settings > Update & Security > Windows Update and select Check for updates.|
|Microsoft Update Catalog||Yes||To get the standalone package for this update, go to the Microsoft Update Catalog website.|
|Windows Server Update Services (WSUS)||No|| |
You can import this update into WSUS manually. See the Microsoft Update Catalog for instructions.
For a list of the files that are provided in this update, download the file information for cumulative update 4516045.