I have the same issue - Windows Update attempts to install "Xerox - Extension - 7.208.0.0" and every time the result is "Download error - 0x800f020b". This occurs every day since 02/17/2021. Windows Update then thinks it is broken and begins to run WaasMedicAgent.exe, a Windows Update repair service which eats up 100% of the system drive I/O for about 40 minutes making the system unuseable while it is running. "Retry" from Windows Update always fails, and I can't fine any way to make it stop trying to install the extension.
Xerox Phaser 6510, latest driver package (XeroxSmartStart_1.5.49.0.exe) is installed and fails to remedy the problem perhaps because I have "Type 3" dirvers installed and Microsloth wants "Type 4"? The latest driver installation fails to install "Xerox Print and Scan Experience" fully. When run it presents an "Install Printers" pane which takes you to the download page for the driver installation you've just run. I attempted to install it from the standalone "XrxSetup_7.192.8.0_x64.msi" but that only runs until the status bar fills up, then says there was an (unspecified) error and rolls back saying the installation "ended prematurely".
I tried the "Type 4" drivers to see if that would solve the problem but those drivers were so lame (apparently dumbed way down for "Windows Store Apps" and cell-phone use) that they just do not work for more complex printing like you would do from Microsoft Office, Adobe Acrobat etc. So I never found out if this would solve the problem.
I also can't seem to figure out if / how you can have both "Type 3" and "Type 4" drivers installed at the same time or if this will solve the extension / Windows Update problem.
