According to the description of the fixes in KB4497935 the bug with the USB devices should have been fixed, but it still does not allow updates with installation media on a USB stick.
"Addresses an issue that may cause an external USB device or SD memory card to be reassigned to an incorrect drive during installation. For more information, see "This PC can't be upgraded to Windows 10" error on a computer that has a USB device or SD card attached"
I tried to do an update with installation media build 18362.145 on a system already at 18362.145 and still gets the error message below:
Is there a fix yet for this bug in the v 1903 release ? Which build do I need to get this bug fixed ?
I know that I can work around the issue installing from a local drive.
Also if I try upgrading from1903 to a preview 20H1 build 18908.1000 using a USB stick the update completes without this message.
I hope we don't need to wait for 20H1 to get this bug resolved.