Today Microsoft released Windows 10 Insider Preview Build 17123 for PC to insiders in the fast ring. While this release brings some bug fixes, it's main focus is the addition of the High Efficiency Image File Format (HEIF) to Windows 10 and continuing to resolve bugs in Windows Mixed Reality.

High Efficiency Image File Format (HEIF) added to Windows 10

With this release, Microsoft has added the High Efficiency Image File Format (HEIF) image format to Windows 10. According to Microsoft:

The High Efficiency Image File Format (HEIF) has arrived for Windows 10 and the Photos app! HEIF is an image container that leverages modern codecs like HEVC to improve quality, compression, and capabilities compared to earlier formats like JPEG, GIF, and PNG. In addition to traditional single images, HEIF supports encoding image sequences, image collections, auxiliary images like alpha or depth maps, live images & video, audio, and HDR for greater contrast. We have heard your feedback that these features and the ability to share photos easily with other platforms is important to you. This release we are delivering essential viewing support (You cannot edit HEIF images in this release).

In order to test this new format, insiders also need to join the Windows App Preview Program for the Photos app, which now supports HEIF. In order to properly test this new format you will need to be using  the March release of the  Photos app (Version 2018.18022.13740.0 or newer).

Windows Mixed Reality changes

In this build, Microsoft continues to iron out bugs in Windows Mixed Reality and wanted to let insiders known about the following known issues.

  • We’re investigating reports of a performance regression for Windows Mixed Reality on hybrid laptops on this build.
  • In some cases, the inbox apps will fail to load inside of Windows Mixed Reality and newly placed Holograms may be empty. Restarting Windows Mixed Reality should resolve both issues.
  • Occasionally there may be a long delay and restart of mixed reality when transitioning to a new place (Skyloft or Cliff House).

Since the last build, the following bugs should now be fixed:

  • The ambient sound in Skyloft should now the correct volume.
  • Launching the Store from Movies & TV should no longer crash either app.
  • 360 videos should render correctly inside of the Edge app, and the 360 Viewer can be launched from directly from the Store app.

Complete list of changes, improvements, and bug fixes for build 17123.

General changes, improvements, and fixes for PC

  • We fixed an issue from the last flight on PCs with the Dolby Access app installed and expired Dolby Atmos license, where the Windows Audio service (audiosrv) would crash with a stack overflow exception and the PC won’t have sound.
  • We fixed an issue resulting in a bug check with the error message SECURE_KERNEL_ERROR in recent flights.
  • As of Build 17063, a change was made that may have caused some older drivers to not load properly. This may have caused update failures or bugchecks (GSODs) shortly after the PC was rebooted. This build includes fixes for this that should prevent these update failures and bugchecks from occurring.
  • Thanks everyone who’s shared feedback about our Embedded Handwriting Panel so far – we’re making a change such that if you clean install, reset your PC, or upgrade straight to this build from the Fall Creators Update this experience will be turned off by default. The setting will remain on for Insiders who have upgraded from previous builds where it was enabled, and can be turned on by anyone with a pen capable device via the “Write directly into text field” option under Pen & Windows Ink Settings.

Known issues

  • If you had your phone linked to your PC prior to upgrading, you’ll find it has become unlinked after upgrading. You can relink your phone from Settings > Phone.

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