Its especially unfortunate since KB4474419, the sha2 update for Windows Seven, defacto disabled updates for quite a few people with dualboot or encrypted system partitions in mid March.
Does this include bitlocker? Or is this an issue with third party boot loaders so bitlocker is fine but truecrypt is not?
edit:
Here some context
https://answers.microsoft.com/en-us/windows/forum/all/kb4474...
its an easy fix for for dualboot if you can just replace grub with mbr again, but people with disc encryption are rather screwed it seems.