Win Server 2012 Boot problems

[puddingtown]

Hi,
I'm using virtualbox on Win2012 Server OS running 2 VM with linux.

After windows updates I'm not able to reboot windows. After uninstalling vb in safe mode windows works fine again and reboot, also reinstalling vb is no problem, but thats nothing I need once in a month. Any idea whats causing that problem?

Regards
Chris