May 9, 2017—KB4019473 (OS Build 10586.916)

Improvements and fixes

This security update includes quality improvements. No new operating system features are being introduced in this update. Key changes include:

• Addressed issue that causes the OS to become unresponsive when migrating users from a cloud-based solution to an on-premise desktop running Microsoft Virtual Desktop Infrastructure.

• Addressed issue with high CPU and RAM usage when accessing .mp4 files larger than 60 GB using Windows Explorer.

• Addressed issue where Windows Event Forwarding between two 2012 R2 servers makes reports incompatible with third-party Security Information and Event Management software.

• Addressed an issue related to establishing a secure connection to a server using the TLS protocol. The application may hang when the server certificate specifies a secure URL (HTTPS) for the Certificate Revocation List (CRL) or for the Authority Information Access (AIA) values within the certificate.

• Addressed issue where applications that use msado15.dll stop working after installing after installing security update KB4015550.

• Addressed issue where the BitLocker Drive Encryption wizard shows the "Choose which encryption mode to use" page even when the BitLocker GPO is enabled.

• Addressed an issue where changing your password while not directly connected to the enterprise network, such as with a VPN, will cause your private keys to become inaccessible. Symptoms vary including the inability to encrypt/decrypt or sign documents.

• Updated Internet Explorer 11’s New Tab Page with an integrated newsfeed.

• Deprecated SHA-1 Microsoft Edge and Internet Explorer 11 for SSL/TLS Server Authentication. See Advisory 4010323 for more information.

• Addressed additional issues with enterprise security, Internet Explorer, and Microsoft Edge.

• Security updates to Microsoft Edge, Microsoft Scripting Engine, Windows COM, Microsoft Graphics Component, .NET Framework, Windows kernel, Windows SMB Server, Windows Server, and Internet Explorer.

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

Microsoft is not currently aware of any issues with this update.

How to get this update

This update will be downloaded and installed automatically from Windows Update. To get the stand-alone package for this update, go to the Microsoft Update Catalog website.

• Update replacement information
  This update replaces the previously released update KB4015219.

• File information
  For a list of the files that are provided in this update, download the file information for cumulative update KB4019473.