Quote:In May, Microsoft officially rolled out the Windows 10 May 2020 Update via Windows Update. Nevertheless, the update was seeded to a limited number of users as the company blocked it on a vast number of devices due to the numerous known issues.

Now, Windows 10 users are complaining about problems with the Media Creation Tool. The tool allows users to upgrade their PCs to the latest Windows update or create a Windows 10 ISO file that can be used to install or upgrade multiple PCs. According to reports on Reddit (via Techdows), users are getting errors while upgrading to Windows 10 May 2020 Update using the Media Creation Tool.
 

Source: Reddit

Microsoft has a support page dedicated to the "0xC1900101" error. The support page lists several workarounds like removing the antivirus and updating the BIOS. Furthermore, the company is also suggested clean installing Windows 10 if none of the workarounds fixes the problem.