The issue affects all Windows machines where system protection is turned on and a system restore point has been created prior to installing one or more Windows 10 updates.Details on how to resolve this issue can be found over here. Microsoft is working on a fix.
When users try to restore the system after the Windows 10 updates have finished installing, the system will not be restored and, instead, "the computer experiences a Stop error (0xc000021a)" and, after restarting the computer, the system will not be able to return to the Windows desktop.
Latest Windows 10 update causes boot issues after System Restore
Posted on Tuesday, May 21 2019 @ 14:16 CEST by Thomas De Maesschalck