If you are having issues with Hyper-V and KB 31661606 you might have a headache coming. If you patched your servers like we did you installed this patch on your Hyper-V hosts along with your Hyper-V guests. So what's wrong with that you say?
If you install this KB it will upgrade the version of the Integration Components for your Hyper-V Server which we have seen happen in the past. The catch is if you have this KB on your guest you will not be able to install the integration components on it. You will probably see error 14101 pop up. This is because the integration components and the patch are trying to update the same file and version. This means you can not have both of them installed on your Guest VM's. You are going to have to pick on or the other for now.......
To install the integration components, uninstall KB 31661606 from your guest VM and reboot. If you still have the install error which my guess is you will, you will also have to run this command to clean things up and reboot again. *Warning this step can take a while to run, so go grab some caffeine, your going to have a lot of work to do*
dism /online /cleanup-image /startcomponentcleanup
Once the integration components are installed you will not be able to install the KB again. It will either time out on Windows Update or if you try to download the patch and run it manually it will fail.
Hopefully Microsoft will come out with a fix soon, and hopefully it will not change the integration components again this soon for the fix.
Needless to say, MY BRAIN HERTZ.......................
