Windows 10 build 21390.1

Windows 10 build 21390.1 is the twentieth Insider Preview build of Cobalt, the 21H2 development semester of Windows as a service, and is the last known build of Windows 10 (excluding CUs) before the announcement of Windows 11. This build was released to the Dev Channel on 26 May 2021.

Changes

 * Task Manager and Windows Installer packages now have updated icons.
 * The Mail and Microsoft Store apps are no longer pinned on the taskbar by default on clean installations.

News and interests
The flyout might occasionally flash in the screen's top left corner when opened.

Camera Settings
The Camera app does not respect the brightness adjustments made to a camera under its respective page.

OOBE
The OOBE may use an incorrect font when this build is ran under Simplified Chinese language pack.

General

 * The update process to this build has a chance of hanging for extended periods of time.
 * Search results in the taskbar flyout are not displaying correctly in the dark theme.
 * The icons for Microsoft Edge and File Explorer in the taskbar are swapped in clean installations.
 * In some cases, audio and video devices that are installed on the system may not work despite showing up in device manager. The chances of the user encountering this bug increases the longer they use this build.

Upgrade

 * There is a chance that the default app mode color will be reverted back to Light from Dark.
 * Sometimes the build may use an incorrect font in several languages.