Yesterday I installed my System Center Virtual Machine Manager. The installation was no problem. The first thing to do was to add my Hyper-V host, running on Windows 2008 R2, to the SCVMM server. Unfortunately there came an error. I got the following error:

Error (2916)
VMM is unable to complete the request. The connection to the agent server.contoso.com was lost.
(Unknown error (0x80338012))

Recommended Action
Ensure that the WS-Management service and the agent are installed and running and that a firewall is not blocking HTTP traffic. If the error persists, reboot server.contoso.com and then try the operation again.

After googling the error I found many possible solutions but none of them worked. My last hit before I went to sleep was the good one. The solution for my problem was the following bug: The “Win32_Service” WMI class leaks memory in Windows Server 2008 R2 and in Windows 7. I installed the hotfix from the KB article and the problem was solved