https://www.bleepingcomputer.com/news/microsoft/microsoft-adds-windows-11-upgrade-block-due-to-ie11-known-issue/

Microsoft has added a new safeguard hold blocking Windows 11 upgrades for Windows 10 customers who don't import their Internet Explorer 11 (IE11) data into Microsoft Edge before trying to install the newest Windows version.

"After upgrading to Windows 11, saved information and data from Internet Explorer 11 (IE11) might not be accessible if you did not accept to import it into Microsoft Edge before the upgrade," Microsoft explained in the Windows health dashboard.