https://www.bleepingcomputer.com/news/microsoft/microsoft-removes-two-windows-10-1903-upgrade-blocks/

Microsoft removed two Windows 10 version 1903 upgrade blocks after resolving the known issues behind them on August 30 with the release of the KB4512941 optional cumulative update.

Both issues were added to the Windows Release Health Dashboard on July 25 and came with compatibility updates designed to safeguard the updated experience of Windows 10 customers.