Windows Insider Preview Build 19577 Released to Fast Ring:
Announcing Windows 10 Insider Preview Build 19577 | Windows Experience Blog.
Note: Please make sure your device is set to “Full” before updating to Build 19577. You will not be able to take future flights if your diagnostic level is left at “Enhanced”. AAD/Domain-joined PCs set to “Enhanced” will be blocked from taking Build 15977. For more information, see this Answers post.
The Build includes changes to the Settings app and Group Policy settings that are part of the Settings app and Group Policy settings. The change in this Build is to Basic diagnostic data which is now known as Required diagnostic data and Full diagnostic data is now Optional diagnostic data. The Build also includes more new icons.
Refer to the blog post for additional changes, fixes and improvements.