Here's what got fixed and is still broken in Windows 10 build 21277

Today, Microsoft released a couple of new Windows 10 Insider Preview builds to the Dev channel. For those that are interested in the rs_prerelease branch, which is literally what the Dev channel was supposed to be for and should be the reason that Insiders signed up, the team released build 21277.

The key new feature in build 21277 is x64 app emulation for ARM64 PCs. However, it also comes with support for Emoji 12.1 and Emoji 13.0 support, and of course, there are a whole bunch of fixes, improvements, and known issues.

Here's what's listed under general changes and improvements. These are UI tweaks that aren't major new features, but they're minor things such as the ability to uninstall Snipping Tool, changes to animations, and so on.

• We’ve updated the animation when opening or closing a window to make the transition smoother. Do you notice a difference? Let us know!
• Based on Insider feedback, you can now use the built-in screen snipping experience in Windows (WIN + SHIFT + S) to create a snip of your screen and paste it directly into a folder of your choice in File Explorer to save the screenshot there. Try it out! (This was released to Windows Insiders in the Beta Channel as part of the recent Windows Feature Experience Pack update.)
• Using the touch keyboard in a portrait posture on a 2-in-1 touch device now supports split keyboard mode. (This was released to Windows Insiders in the Beta Channel as part of the recent Windows Feature Experience Pack update.)
• It’s now possible to uninstall the Snipping Tool. If you choose to uninstall it, it can be reinstalled via the Optional Features page in Settings.
• We’ve made some adjustments to improve the scaling logic of the graphs in Task Manager’s Performance tab.
• We’ve updated Registry Editor so that the Find window, renaming a key, and other places all now support CTRL + Backspace to delete words at a time.
• When using the Delete key or Dismiss button in Action Center to clear groups of notifications, Narrator will now announce that the notification group has been cleared instead of just moving focus to the next notification group.
• Based on feedback we’re adjusting a few strings in Offline Maps Settings to improve clarity.
• To help you find what you’re looking for faster, we’ve updated our folder logic in Start menu’s all apps list so that if a folder only contains a single item we will now display that item in place of the folder.

Here's the list of fixes:

• We fixed an issue resulting in some users seeing error 0x80070426 when using their Microsoft account to sign into various apps.
• We fixed an issue where limiting a search in File Explorer to a specific folder was unexpectedly returning results from the subfolders.
• We fixed an issue resulting in a “The directory name is invalid” error appearing when trying to open a file from a saved File Explorer search.
• We fixed an issue where after doing a search from within File Explorer and clicking the arrow next to a column header to see a list of available filters for the results, it would get stuck on “Computing Filters…” and never actually displays any filters.
• We fixed an issue where the apostrophe in the tooltips for Power options in Start menu wasn’t displaying correctly.
• We fixed an issue that could result in Microsoft Edge windows unexpectedly being grouped with File Explorer in the taskbar.
• We fixed an issue that could result in explorer.exe crashing when switching virtual desktops using a touchpad gesture.
• We fixed an issue that could result in acrylic unexpectedly not be applied to the login screen if you used the option in Start to switch users.
• We fixed a deadlock that could result in the Windows Security icon in the notification area continually displaying an alert although the Windows Security app had no alerts.
• We fixed a typo in Settings > Privacy > Notifications.
• We fixed an issue impacting the loading performance of Sign-in Settings for some users.
• We fixed an issue where the ms-settings:signinoptions-launchsecuritykeyenrollment URI wasn’t opening the security key management options in Sign-in Settings.
• We fixed an issue that could result in your name and profile image being unexpectedly missing from the banner at the top of Settings.
• We fixed an issue that could result in Windows Update Settings saying battery saver was enabled when it wasn’t.
• We fixed an issue that could result in you unexpectedly seeing a message when shutting down saying “Closing 1 app and signing out. Task Host is stopping background tasks” related to syncing language settings, even though no apps were open.
• We fixed an issue resulting in printers with Japanese characters in their names not displaying correctly in Printers & Scanners Settings.
• We fixed an issue where Background Settings was still displaying a link to “Sync your settings” although this option is no longer supported.
• We fixed an issue resulting in some apps in Apps & Features Settings to display unexpectedly dimmed.
• We fixed an issue that could result in no screenshot being copied to your clipboard after pressing WIN + Shift + S.
• We fixed an issue that could result in a bug check with error IRQL_NOT_LESS_OR_EQUAL when playing games with hardware-accelerated GPU scheduling enabled.
• We fixed an issue where a slight drag on a modifier key on the touch keyboard (such as CTRL or Shift) while it was being held down could result in the key becoming stuck down.
• We fixed an issue where the clipboard icon in the touch keyboard (when there was content available to be pasted) was unexpectedly small.
• We’ve fixed a few issues impacting touch keyboard performance.
• We fixed an issue impacting touch keyboard reliability in the last few flights.
• We fixed an issue where when using high contrast, the border of some keys in the touch keyboard were the same as the key color.
• We fixed an issue where when using high contrast items in the touch keyboard’s language list were unexpectedly using the disabled text color.
• We fixed an issue impacting touch keyboard usage with Narrator.
• We fixed an issue where after selecting a clipboard history item from the touch keyboard, it might not be possible to subsequently select text candidates.
• We fixed an issue where the touch keyboard would crash if you tried to input a character using a child key into a password field.
• We fixed an issue for touch keyboard users, where, after restarting explorer.exe, it could result in explorer.exe getting stuck in a restart loop.
• We fixed an issue where the Japanese IME may not display the current furigana in a string after reconversion.
• We fixed an issue where the kana input mode state in the Japanese IME’s context menu could get out of sync with the actual state.
• We fixed an issue when using the Japanese IME resulting in an unexpected, continued increase in ctfmon.exe handle usage after every focus switch.
• We fixed an issue where when typing using the Japanese IME in a browser’s URL bar, after using space to convert your string the up / down arrows to select the browser suggestions wouldn’t work.
• We’ve made a few fixes to address craftsmanship issues with the new voice typing experience.
• We fixed an issue where trying to use voice typing with when airplane mode was enabled would result in an expectedly large authentication pop up appearing.
• We fixed an issue where voice typing could get stuck initializing and never start listening.
• We fixed an issue where if voice typing was open and you switched languages, it might unexpectedly start listening again.
• We fixed an issue where the close button on notifications wasn’t working with touch.
• We fixed an issue resulting in the Action Center sometimes unexpectedly showing blank when there were available notifications.
• We fixed an issue where the margin from a notification to the taskbar wasn’t the same as the margin from a notification to the side of the screen.
• We fixed an issue that could result in the Focus Assist quick action not responding, and going to Focus Assist Settings, crashing Settings pages.
• We fixed an issue where if you launched Notepad by running %windir%\notepad.exe, then Notepad’s icon wouldn’t display correctly in the title bar.
• We fixed an issue that could result in you seeing your display turn on after existing Modern Standby but shortly afterwards bug check saying that it took too long for the display to turn on.
• We fixed an issue resulting in some Insiders seeing a bug check recently citing an issue with Memory Management.
• We fixed an issue resulting in some Insiders seeing a bug check recently saying System Service Exception.
• We fixed an issue that could result in sections of Task Manager’s Performance tab not responding to mouse scroll wheel or touchpad pan events.
• We fixed an issue where the Power Usage and Power Usage Trend columns in Task Manager weren’t showing arrows indicating directionality when sorting by that column.

Finally, here's what's still broken:

• We’re working on a fix for an issue resulting in some users seeing a popup that says “Your PC ran into a problem and will restart in 1 min” after logging in to Windows with either an Azure Active Directory or Active Directory account. If you encounter it, please save any data immediately and your system will restart automatically.
• We’re looking into reports of the update process hanging for extended periods of time when attempting to install a new build.
• Live previews for pinned sites aren’t enabled for all Insiders yet, so you may see a grey window when hovering over the thumbnail in the taskbar. We’re continuing to work on polishing this experience.
• We’re working on enabling the new taskbar experience for existing pinned sites. In the meantime, you can unpin the site from the taskbar, remove it from the edge://apps page, and then re-pin the site.
• We’re working on a fix for an issue where no drives appear under Settings > System > Storage > Manage Disks and Volumes. As a workaround, you can manage your disks in the classic Disk Management tool.

As always, you can grab the build via Windows Update, but you do have to opt into accepting it instead of the default build 20277. If you're not on the Dev channel, you can enroll via the Windows Insider Program tab.