A new preview build of Windows 10 has been released for the Windows Insiders enrolled on the Fast ring. Similar to previous builds released through Fast ring after the official release of Windows 10 Version 2004, the build is from mn_release (Manganese) branch, and is expected to receive new builds in this branch until end of June when release branch is expected to switch to Fe (Iron) branch.

Windows 10 Build 19640.1 does not add any new features or functionality, which is normally the case at feature freeze stage when a branch is near completion as release candidate. However, it does contain several bug fixes and improvements to existing features.

The changelog Windows 10 Build 19640 changelog is as follow:

General changes & improvements

  • If the your Downloads folder is synced to a cloud provider, the option to have Storage Sense automatically clear out the Downloads folder on a cycle is disabled.
  • Starting the username with a space no longer results in an error when logging in.

Known issues

  • Some devices booting from eMMC storage bugchecked when resuming from hibernate.
  • The update process hanging for extended periods of time when attempting to install a new build.
  • In Settings > Privacy, the Documents and Downloads sections show a broken icon next to their page name (just a rectangle).
  • Taskbar preview thumbnails aren’t rendering consistently (showing a blank area).
Windows 10 Product Family

To download and install Windows 10 Build 19640.1, join Windows Insider program and set to setting to Fast ring. Then, check for updates in Settings -> Update & Security -> Windows Update to receive the latest build available.

Update: Windows 10 Build 19645