A new Windows 10 SDK Insider Preview that's available for download. It appends the Windows 10 Insider Preview build 18950 that was recently released to the Fast Ring. Here are the changes in this release.

The Preview SDK 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 and 2019. You can install this SDK and still also continue to submit your apps that target Windows 10 build 1903 or earlier to the Microsoft Store.
• The Windows SDK will now formally only be supported by Visual Studio 2017 and greater. You can download the Visual Studio 2019 here.
• This build of the Windows SDK will install on only on Windows 10 Insider Preview builds.
• In order to assist with script access to the SDK, the ISO will also be able to be accessed through the following static URL: https://software-download.microsoft.com/download/sg/Windows_InsiderPreview_SDK_en-us_18950_1.iso.

Tools Updates

Message Compiler (mc.exe)

• Now detects the Unicode byte order mark (BOM) in .mc files. If the If the .mc file starts with a UTF-8 BOM, it will be read as a UTF-8 file. Otherwise, if it starts with a UTF-16LE BOM, it will be read as a UTF-16LE file. If the -u parameter was specified, it will be read as a UTF-16LE file. Otherwise, it will be read using the current code page (CP_ACP).
• Now avoids one-definition-rule (ODR) problems in MC-generated C/C++ ETW helpers caused by conflicting configuration macros (e.g. when two .cpp files with conflicting definitions of MCGEN_EVENTWRITETRANSFER are linked into the same binary, the MC-generated ETW helpers will now respect the definition of MCGEN_EVENTWRITETRANSFER in each .cpp file instead of arbitrarily picking one or the other).

Windows Trace Preprocessor (tracewpp.exe)

• Now supports Unicode input (.ini, .tpl, and source code) files. Input files starting with a UTF-8 or UTF-16 byte order mark (BOM) will be read as Unicode. Input files that do not start with a BOM will be read using the current code page (CP_ACP). For backwards-compatibility, if the -UnicodeIgnore command-line parameter is specified, files starting with a UTF-16 BOM will be treated as empty.
• Now supports Unicode output (.tmh) files. By default, output files will be encoded using the current code page (CP_ACP). Use command-line parameters -cp:UTF-8 or -cp:UTF-16 to generate Unicode output files.
• Behavior change: tracewpp now converts all input text to Unicode, performs processing in Unicode, and converts output text to the specified output encoding. Earlier versions of tracewpp avoided Unicode conversions and performed text processing assuming a single-byte character set. This may lead to behavior changes in cases where the input files do not conform to the current code page. In cases where this is a problem, consider converting the input files to UTF-8 (with BOM) and/or using the -cp:UTF-8 command-line parameter to avoid encoding ambiguity.

TraceLoggingProvider.h

• Now avoids one-definition-rule (ODR) problems caused by conflicting configuration macros (e.g. when two .cpp files with conflicting definitions of TLG_EVENT_WRITE_TRANSFER are linked into the same binary, the TraceLoggingProvider.h helpers will now respect the definition of TLG_EVENT_WRITE_TRANSFER in each .cpp file instead of arbitrarily picking one or the other).
• In C++ code, the TraceLoggingWrite macro has been updated to enable better code sharing between similar events using variadic templates.

Signing your apps with Device Guard Signing

• We are making it easier for you to sign your app. Device Guard signing is a Device Guard feature that is available in Microsoft Store for Business and Education. Signing allows enterprises to guarantee every app comes from a trusted source. Our goal is to make signing your MSIX package easier. Documentation on Device Guard Signing can be found here: https://docs.microsoft.com/windows/msix/package/signing-package-device-guard-signing

Breaking Changes

Removal of IRPROPS.LIB

In this release irprops.lib has been removed from the Windows SDK. Apps that were linking against irprops.lib can switch to bthprops.lib as a drop-in replacement.

API Updates, Additions and Removals

A number of APIs have been added to the platform since the release of Windows 10 SDK, version 1903, build 18362.

If you're a software developer running WIndows 10 Insider Preview build 18950, it is good to have this SDK installed.

Source: Microsoft