We have SmarterTrack 10 installed on a Server 2008 R2 instance.  After installing KB3051768 (released May 12, 2015) SmarterTrack stopped working.  Uninstalled it and SmarterTrack started working again.  Updated SmarterTrack to the latest 10 version at the time (10.6.5605).  Installed KB3051768 again and rebooted and SmarterTrack would stop working again.  The odd thing is that it wouldn't seem to fail right away.  At first I could log on to the site, then later I would get an error.  The spool would stop working (both incoming and outgoing if I remember correctly).  Uninstalling (with a reboot) always fixed the problem (I did it about 4 times).