Microsoft released out-of-band (OOB) KB5015020 (OS Builds 19042.1708, 19043.1703, and 19044.1708) for Windows 10 versions 21H2, 21H1, and 20H2.
The update addresses an issue that might prevent you from installing Microsoft Store apps.
If your device does not have the May 11, 2021 (KB5003173) or later LCU, you must install the special standalone August 10, 2021 SSU (KB5005260) before installing this update.
Update: To get the update, go to Settings > Update & Security > Windows Update. The link to download and install the update can be found in the Optional updates available area. To get the standalone package for this update, go to the Microsoft Update Catalog website.
Windows 10 update history
The update addresses an issue that might prevent you from installing Microsoft Store apps.
If your device does not have the May 11, 2021 (KB5003173) or later LCU, you must install the special standalone August 10, 2021 SSU (KB5005260) before installing this update.
Update: To get the update, go to Settings > Update & Security > Windows Update. The link to download and install the update can be found in the Optional updates available area. To get the standalone package for this update, go to the Microsoft Update Catalog website.
Windows 10 update history