Here's the changelog for Windows 10 Build 10586.456 for PC and Mobile

Microsoft released a new build of Windows 10 for the Release Preview ring just yesterday. The released build 10586.456 (KB3170411) to Insiders yesterday on both PC and Mobile. As usual, the update doesn’t introduce any new features, but it includes several bug fixes and improvements. Today, Microsoft shared the official changelog for build 10586.456. According to the changelog, Microsoft has improved reliability for some of the key features of Windows, including the Windows Explorer, Kernel, Miracast, and the Windows Media Player. Here is the full changelog:

• Improved reliability in a number of areas including Windows Media player, Internet Explorer 11, Windows Explorer, Miracast, and Windows kernel.
• Fixed an issue with some users noticing a black screen instead of the lock screen, when resuming from connected standby.
• Fixed issue where the DirectAccess Disconnect button appears sometimes even when the connection is not fully established.
• Fixed issue where local user accounts weren’t locked out after a number of failed sign in attempts.
• Improved support for playback of video in certain applications that did not render the video while the audio continued after resuming from sleep.
• Fixed issue where the Windows Phone sometimes loses user authentication certificates after upgrading to Windows 10 Mobile.
• Improved support to honor the data backup settings of applications on Windows 10 Mobile.
• Fixed issue where Microsoft Silverlight based application won’t install on Windows 10 Mobile, after joining Azure Active Directory.
• Fixed additional issues in .NET, Windows Kernel, Windows Update, Authentication, revised daylight saving time, support for PDF files, Bluetooth, Microsoft Edge, Internet Explorer, Networking and Wi-Fi connectivity.

As you may notice, Microsoft has also fixed a few issues on Windows 10 Mobile wth build 10586.456. It is worth noting that this build will be coming to the public if it passes internal testing and Microsoft doesn’t find any critical bugs. If this happens, Microsoft may release this to the public next Tuesday for both PC and Mobile.