Microsoft has updated the Fast Ring by releasing Windows 10 Build 19640 to Insiders. There are no new features in this build. Instead, it includes a few fixes .

General changes & improvements

• Based on feedback, if your Downloads folder is synced to a cloud provider, we are disabling the option to have Storage Sense automatically clear out your Downloads folder on a cycle.
• We updated our login logic, so if your PC is set up so you need to type in your username when logging in, accidentally starting your username with a space will no longer result in an error.

Known issues

• We’re looking into an issue where some devices booting from eMMC storage bugchecked when resuming from hibernate.
• We’re looking into reports of the update process hanging for extended periods of time when attempting to install a new build.
• We’re working on fixing an issue for a future Insider Preview build where in Settings > Privacy, the Documents and Downloads sections show a broken icon next to their page name (just a rectangle).
• We’re looking into reports that taskbar preview thumbnails aren’t rendering consistently (showing a blank area).