Windows 10 build 17123

Windows 10 build 17123 is the twenty-second Insider Preview build of Windows 10 April 2018 Update. This build was released to Windows Insiders in the Fast Ring on 16 March 2018.

Changes

 * Windows now supports the High Efficiency Image File Format (HEIF).
 * General improvements, changes and bug fixes listed in the official announcement.

Mixed Reality

 * If you're using a hybrid laptop, performance of Mixed Reality may be significantly reduced.
 * Sometimes inbox apps will fail to load inside Mixed Reality and newly placed holograms may be empty. Restarting should fix both issues.
 * Sometimes it takes an abnormally long time to load the cliff house and Skyloft, and the app may occasionally restart itself while doing so.

Other

 * If you had your phone linked to your PC prior to upgrading to this build, it will become unlinked after the upgrade.