After installing KB2775511 on Operations Manager Management Servers, agents or servers may be affected by a deadlock.
Once in deadlock, Management Servers will generate Heart Beat failures and will go into a “greyed out” state. grayed out. As a result, devices managed by these Management Servers will also go into a “greyed out” or “not monitored state.”
When in this state:
Removal of KB2775511 will correct the issues introduced. The OpsMgr team recommends that Operations Manager users refrain from installing KB2775511 until this deadlock issue is resolved. New information will be posted as it becomes available.
So DON’T install KB2775511 since it will render your SCOM environment useless. This KB affects SCOM Agents, SCOM Management Servers and SCOM Gateways!