Windows 10 Anniversary Update Build 10.0.14251

Build 14251 was the 4th Insider Preview build of Windows 10 Redstone series. It was released on January 27, 2016. This build arrived via new "RS1" (RedStone1) development branch.

New and Changes

• Improvements to OneCore

·         The build syncs the desktop and mobile version, bumping it to Build 14251

Fixed Issues

• Fixes an issue where some PC games would crash when switching from windowed mode to full screen
• Fixes an issue where Narrator, Magnifier and other third-party assistive programs may encounter issues
• Fixes an issue where File Explorer would crash on 175%

Known Issues

·         A WSClient.dll error dialog might appear after logging in

·         The Connect button does not appear in Action Center

·         Apps may periodically crash or other memory related issues

·         F12 Developer Tools in Edge are broken

·         Using "Reset This PC" would make your PC unusable

source: windows blog

April 02, 2016