Windows 10 19H1*preview build*18277 is now rolling out to the Insiders in the Fast and Skip Ahead Ring with some notable improvements. This test build improves Focus Assist feature, Action Center, introduces new Emojis and more.
Focus assist improvements


With Windows 10 April 2018 Update, Microsoft introduced Focus Assist, a useful feature that helps you stay productive by blocking notifications, sounds, and alerts. This is a helpful feature if you're working on an important project or playing a game.
Windows 10 19H1*update is going to improve Focus Assist behavior. In a blog post, Microsoft notes that Focus Assist will be enabled automatically if you're doing anything in full-screen mode. You will find this option under Settings > System > Focus Assist and you should enable it if you use full screen mode for watching movies, studying notes and similar activities where you'd like to keep your notifications quiet until you exit full screen mode.
Action Center improvements


Action Center is getting better with Windows 10 19H1 update as Microsoft is finally adding a*brightness slider. You can now easily customize your screen brightness using the slider. Previously, the users were required to tap on the brightness button to change the level.
Microsoft is also adding a new feature to the Action Center that would allow you to customize the quick actions right from the Action Center itself. Just like how you can customize the*Android's phone notification panel, you can now arrange the actions on Windows 10's Action Center and add any quick action you need on the fly, without opening the settings page.
Emoji 12


Microsoft is preparing for big emoji update and some of the new*emojis are available for use via the emoji panel (WIN + .) and the touch keyboard.
DPI Improvements


In Windows 10 19H1, Microsoft will enable the advanced DPI settings by default to automatically address the scaling problems experienced on some systems. This change will reduce the number of times you see that “Fix blurry apps” notification on the Action Center.
Snipping Tool improvements

Microsoft is testing some new features in Windows 10 that would improve the snipping experience*but at the moment the details are not available.*"Some Insiders may notice changes to our snipping experiences, as we explore ideas for the future – we’ll have more details to share later," Microsoft explains.
General changes, improvements, and fixes for PC

  • We fixed the issue causing WSL to not work in Build 18272. Thanks for your patience.
  • We fixed an issue resulting in text not rendering on the screen if you had a large number of OTF fonts, or had OTF fonts that support the extended East Asian character set.
  • We fixed a recent issue where Task View failed to show the + button under New Desktop after creating 2 Virtual Desktops.
  • We fixed an issue resulting in Timeline crashing explorer.exe if you pressed ALT+F4 while it was visible.
  • We fixed an issue significantly impacting Start menu reliability in recent builds when pinning, unpinning, or uninstalling apps.
  • We fixed an issue where the expected context menu wouldn’t appear after right-clicking on a folder in File Explorer from a network location.
  • Some Insiders may notice small differences in File Explorer over the coming flights – we’ll have more to share later about this later.
  • We fixed an issue resulting in the home page of Settings having no visible scrollbar in recent flights if the window was small enough to need one.
  • We’re updating the icon used to identify the Region page in Settings.
  • We fixed an issue resulting in Settings crashing sometimes in recent flights when going to Sign-in Settings.
  • We fixed an issue where Settings would crash if you were typing in the search box with the embedded handwriting panel and went to switch languages within the panel.
  • We fixed an issue where playing videos might unexpectedly show a few frames in the wrong orientation when maximizing the window after changing the orientation of your screen.
  • We fixed an issue impacting Emoji Panel reliability in recent flights.
  • The touch keyboard’s feature to input a period after two quick taps on the spacebar was recently also accidentally enabled when typing with the hardware keyboard and has now been disabled.
  • We’ve made some adjustments to improve the performance of WIN+Shift+S bringing up snipping.
  • Some Insiders may notice changes to our snipping experiences, as we explore ideas for the future – we’ll have more details to share later.
  • We fixed an issue that caused*Far Manager*to have a significant pause during a long running command like ‘dir’ (see*Microsoft/console#279).
  • We fixed an issue that caused Windows applications running from WSL through interop and applications using the**PseudoConsole APIs*to redraw the top left corner excessively (see*Microsoft/console#235).
  • We fixed an issue resulting in running “start .” from Command Prompt failing in the previous flight with an access denied error.
  • We fixed an issue resulting in some Insiders experiencing bug checks (green screens) with the error KMODE_EXCEPTION_NOT_HANDLED on the previous flight.
  • We fixed an issue where certain devices might hit a bug check (GSOD) when shutting down or when switching from a Microsoft account to a local admin account.
  • We fixed an issue resulting in wuaueng.dll repeatedly crashing in the background for some Insiders in the last few flights.

Known issues

  • Some users will notice the update status cycling between Getting Things Ready, Downloading, and Installing. This is often accompanied with error 0x8024200d caused by a failed express package download.
  • PDFs opened in Microsoft Edge may not display correctly (small, instead of using the entire space).
  • We’re investigating a race condition resulting in blue screens if your PC is set up to dual boot. If you’re impacted the workaround is to disable dual boot for now, we’ll let you know when the fix flights.
  • The hyperlink colors need to be refined in Dark Mode in Sticky Notes if the Insights are enabled.
  • Settings page will crash after changing the account password or PIN, we recommend using the CTRL + ALT + DEL method to change the password
  • Due to a merge conflict, the settings for enabling/disabling Dynamic Lock are missing from Sign-in Settings. We’re working on a fix, appreciate your patience.

Known issues for Developers

  • If you install any of the recent builds from the Fast ring and switch to the Slow ring – optional content such as enabling developer mode will fail. You will have to remain in the Fast ring to add/install/enable optional content. This is because optional content will only install on builds approved for specific rings.