What’s coming in the next major update of Windows 10?

Insider builds of Windows 10 let users, like you, test new versions of Window 10 before the updates, improvement, new features and fixes  are placed in the Windows Update download cycle. The current version of Windows 10 is 10586.218 . If you’re on the fast track for updates then you undoubtedly have a newer version. A reminder: Using pre-release versions of Windows on your main computer may result in loss of data and/or unexpected, unpleasant consequences.

Never fast track updates on your main computer. We warned you.  That’s like a warning on a pack of cigarettes, I know. People who are going to smoke are going to smoke even if the package said: “Smoking these cigarettes could turn your head into a ball of cow dung.” But hey, we warned you about installing preview builds of Windows on your main computer; if you do it and the worst happens, don’t blame aunt Darcy or uncle TC. We warned you twice, I tells ya!

You may be familiar with some of the problems that this preview build fixes, because you had or are having the problem(s) described. The good news is that if it’s listed as “Fixed” below, it will be fixed on your PC with the next major Windows 10 update.

Windows Preview Build 14342 was released to Windows “Insiders” on 10 May 2016. Here’s the scoop from the Microsoft Windows Blog:
Announcing Windows 10 Insider Preview Build 14342

Here’s what’s fixed for PC

1. We have fixed the issues blocking the Desktop App Converter Preview (Project Centennial). You can now run the converter on the Enterprise edition as well as Pro edition of Windows. You will need the latest converter and base image from here to take advantage of all the improvements which will be available later today.
2. We fixed the issue causing Tencent online games from not working in current builds from the Development Branch.
3. We have fixed the issue causing DRM-protected content from services like Groove Music, Microsoft Movies & TV, Netflix, Amazon Instant Video or Hulu from being playable with playback with 0x8004C029 or 0x8004C503 errors.
4. We fixed an issue resulting in audio crashes for users who play audio to a receiver over S/PDIF or HDMI, and use a driver that supports real-time encoding via technologies like Dolby Digital Live or DTS Connect.
5. Polished the animation when invoking Cortana on the Lock screen. And also resolved an issue where tapping the link to fix mic issues wouldn’t fix them.
6. We fixed an issue resulting in the ok/cancel buttons in the network flyout being clipped on high DPI devices.
7. We fixed an issue where you might see Windows Hello messages on the screen while you were already logging in with a fingerprint.
8. We fixed the issue where if you were in an app and clicked on a link with a URL longer than 260 characters, it would bring up the “Open with…” dialog instead of opening with your default browser.
9. We fixed an issue resulting in not being able to use your mouse in the Photos app to either move photo while zoomed or adjust crop region.
10. The ALT + Y keyboard shortcut to choose “yes” now works with the updated UAC UI.
11. Updated new Credential UI to add support for pasting into username and password fields.
12. Polished icons used to identify pages in the Settings app – in particular, updated battery icon to be more consistent with the weight of the other icons.
13. Made some polish improvements to the Action Center, and resolved an issue where icon in Taskbar wasn’t displaying correctly at 175% DPI.
14. We fixed an issue where the image used in Screen Sketch would be rotated 90 degrees for native portrait devices (such as the Dell Venue 8 Pro). Also polished the experience of cropping images in Screen Sketch.
15. We fixed Clock and Calendar flyout issues on the taskbar with the 24-hour time format where the agenda items would display using 12-hour format instead of the 24-hour time format and certain items would be off by 12 hours.
16. We fixed an issue where the Clock and Calendar flyout couldn’t be dismissed by clicking on the date and time in the taskbar a second time.
17. We updated the “set location” notification so tapping anywhere in the notification will now enable you to set a default location.
18. We fixed an issue where certain shortcuts weren’t working in UWPs, for example CTRL + C, CTRL + V, and ALT + Space.
19. We fixed an issue where tapping the battery icon wouldn’t open the Battery flyout when in Tablet Mode.
20. We fixed an issue where clicking elements in the Start navigation pane might result in the Store opening instead.
21. We fixed an issue where background audio tasks might show up in the volume controls.
22. We added a “Clear Input History” option to the IME Settings page.
23. We fixed an issue where doing an action on a file in a folder pinned to Quick Access after using the address bar to get there might result in File Explorer unexpectedly navigating to Quick Access.
24. We fixed an issue resulting in Cortana crashing if you shared an avatar with Cortana from the Xbox Avatars app.
25. We fixed an issue causing the search box on the Language Settings page to not work.

Known issues for PC

1. Feedback Hub is not localized and the UI will be in English (U.S.) only, even with language packs installed.
2. Feedback Hub takes about 20-30 minutes after updating to this build to download and populate itself if launched from Start. If you launch Feedback Hub from All apps – it will force the app to hydrate.
3. Symantec products such as Norton Antivirus and Norton Internet Security are causing PCs to bluescreen (bug check).
4. The QQ app from Tencent crashes. We’re working on a fix for the issue.
5. If you are using a non-English keyboard, you can’t accept Bash prompts.
6. We are investigating an issue where if you’re running Insider Preview builds in certain languages, the All apps list on Start appears empty. A workaround for this is to use search to launch apps.
7. You may see square boxes in certain apps when using some of the new emoji – we’re still getting things set up, this will be resolved in a future build.

Microsoft Source: https://blogs.windows.com/windowsexperience/2016/05/10/announcing-windows-10-insider-preview-build-14342/#RjWiK3pVIvVszrAZ.99