Weird problem here. I've got a Windows 10 VM that used to work. But now it always fails with an 0xc000021a error. I tried to google a solution but I have failed so far :(
I've tried running sfc /scannow as well as Dism /Online /Cleanup-Image /RestoreHealth (after having successfully booted in Windows 10 by using 'disable driver signature enforcement' in the 'startup settings' of the troubleshoot menu.
Any other ideas? Thanks!