I was working with several different VMs this morning, created a new one, and suspended one machine with a saved state, and got notice of windows updates. Installed these updates and rebooted.
the updates are
KB3008923
KB3013126
KB3004394
KB3006121
KB3006625
KB3009736
KB3013410
KB3014406
KB890830
KB2310138 (an optional security essentials)
After reboot, the machine in the suspended state wouldn't start up. Tried the other ones, none of them would start up either. Each of them gave a message similar to:
Failed to open a session for the virtual machine MyMachineName.
The VM session was closed before any attempt to power it on.
Details:.....
I did a system restore to what it was yesterday and rebooted and all the VMs start up fine.
Installed KB3004394 alone and rebooted, problem reappeared. Restored system again to yesterday's state via system restore and then did all the other updates, one by one, restarting between them and VB worked fine.
Then did KB3004394 again, rebooted, problem reappeared, restored system sans KB3004394, and all is working well again.
I've attached the logs, the time of the last error was approximately 12:29 p.m. CST but it occurred earlier also. This is a Fedora 21 guest, freshly installed but that probably doesn't matter as none of the other VMs worked either. Running on Windows 7 Ultimate as host.
Edit: I may have the error msg. wrong and think shoreditch has the proper one. I didn't save error msg. correctly and gathered it from my browser history.