August 22, 2017 10:59 am

Windows 10 SDK Preview Build 16267 and Mobile Emulator Build 15240 Released

By / Senior Technical Product Manager, Windows Developer Team

Today, we released a new Windows 10 Preview Build of the SDK and the Mobile Emulator to be used in conjunction with Windows 10 Insider Preview (Build 16267 or greater). The Preview SDK Build 16267 contains bug fixes and under development changes to the API surface area.

The Preview SDK and Mobile Emulator can be downloaded from developer section on Windows Insider.

For feedback and updates to the known issues, please see the developer forum. For new developer feature requests, head over to our Windows Platform UserVoice.

Things to note:

  • This build works in conjunction with previously released SDKs and Visual Studio 2017. You can install this SDK and still continue to submit your apps that target Windows 10 Creators build or earlier to the Windows Store.
  • The Windows SDK will now formally only be supported by Visual Studio 2017 and greater. You can download the Visual Studio 2017 here.

Known Issues

  • Compilation fails on non-Windows 10 platforms
    When building apps on previous platforms, you may get a build error:

C:\program files (x86)\Windows Kits\10\bin\10.0.16232.0\x86\genxbf.dll:C:\program files (x860\Windows Kits\10\bin\10.0.16232.0\x86\genxbf.dll(0,0): Error WMC0621: Cannot resolve ‘GenXbf.dll’ under path ‘C:\program files (x860\Windows Kits\10\bin\10.0.16232.0\x86\genxbf.dll’.  Please install the latest version of the Windows 10 Software Development Kit.
Process ‘msbuild.exe’ exited with code ‘1’.

This will occur if the minimum target platform version is set to 10.0.16225.0. To work around this, right click on your project file and choose properties or open your project file in your favorite editor, and change the version to a previous released SDK. For example:


Breaking Changes

  • ecmangen.exe removal from the SDK: Ecmangen.exe will no longer ship with the Windows SDK. Developers who rely on ecmangen for event manifest creation are advised to install the Windows Creators Edition of the SDK to obtain the file. Developers may also use notepad or other XML editor of choice for manifest creation. A schema file is available on MSDN to aid in manifest creation, for tools that support it.

API Updates and Additions

When targeting new APIs, consider writing your app to be adaptive in order to run correctly on the widest number of Windows 10 devices. Please see Dynamically detecting features with API contracts (10 by 10) for more information.

The following are the API changes since the 16257 Preview SDK, please reference that list.

Additions to Preview SDK 16257

namespace Windows.Storage.Provider {
  public enum HardlinkPolicy : uint
  public enum HydrationPolicy {
    AlwaysFull = 3,
    Partial = 0,
  public enum InSyncPolicy : uint {
    DirectoryLastWriteTime = (uint)512,
    FileLastWriteTime = (uint)256,
  public enum PopulationPolicy {
    AlwaysFull = 2,
  public sealed class StorageProviderSyncRootInfo {
    HardlinkPolicy HardlinkPolicy { get; set; }
namespace Windows.UI.WebUI {
  public sealed class WebUIStartupTaskActivatedEventArgs : IActivatedEventArgs, IActivatedEventArgsDeferral, IActivatedEventArgsWithUser, IStartupTaskActivatedEventArgs {
    ActivatedOperation ActivatedOperation { get; }

Removals from Preview SDK 16257

namespace Windows.Storage.Provider {
  public enum HydrationPolicy {
    NoPartial = 3,
    OnDemand = 0,
  public enum PopulationPolicy {
    NoPartial = 2,