A new test build of Windows 10 Insider Preview Build 19640 (Manganese) is available for members of the Windows Insider program with an update priority of Early Access.
Windows 10 Insider Preview build 19640.1 – an assembly that belongs to the mn_release (Manganese) development branch, is available to Windows Insider program participants with the priority of receiving Early Access updates.
Full build number: 19640.1.mn_release.200530-1731
Transition to the MN_RELEASE development branch
Starting with Windows 10 Build 19628, the name of the development branch from which Microsoft releases assemblies has changed to MN_RELEASE. As we mentioned in December, Microsoft has changed its approach to testing Windows 10, and insiders on the Early Access channel get builds directly from this Active Development Branch. As Microsoft explains:
In this case, we are developing our ability to change which branch we consider to be the active development branch. This is only a short-term change, and we intend to soon release assemblies within the framework of RS_PRERELEASE. Since our engineers work in development cycles within the company, we can prioritize work in a particular branch and we may need to move insiders between branches. Builds from the MN_RELEASE branch do not apply to any specific release of Windows 10.
New in Windows 10 build 19640
Changes and Improvements
If the Downloads folder is synchronized with cloud storage, the Memory Control feature will not automatically clear this folder.
Logon logic updated. Now, if your computer requires you to enter a username at login, accidentally entering a username with a space will no longer result in an error.
Some devices that boot from eMMC drives may run error checking when exiting hibernation mode.
The problem reports with the update process that has been hanging for a long period of time when trying to install a new assembly are examined.
The Documents section in the Privacy section has an incorrect icon (just a rectangle).
The taskbar preview thumbnails are displayed unevenly (an empty area is displayed).