How to troubleshoot issues that occur when you add a Hyper-V host in System Center Virtual Machine Manager

Applies to: Microsoft System Center 2012 R2 Virtual Machine ManagerSystem Center 2012 Virtual Machine ManagerSystem Center 2016 Virtual Machine Manager

Home users: This article is only intended for technical support agents and IT professionals. If you're looking for help with a problem, please ask the Microsoft Community.


This article describes how to troubleshoot issues that occur when you add a Hyper-V host in System Center 2012 and later versions of Virtual Machine Manager. 

The following errors are typically logged in the VMM Console when an “Add virtual machine host” job fails:

Error (421)
Agent installation failed on because of a WS-Management configuration error.

Error (2912)
An internal error has occurred trying to contact an agent on the server.

Error (2916)
VMM is unable to complete the request. The connection to the agent was lost.

Error (2927)
A Hardware Management error has occurred trying to contact server

To determine the cause of the issue, follow the steps in the "More Information" section.

More Information

Step 1: Review the VMM Agent installation log file

On the Hyper-V host, review the vmmAgent.msi_date_time.log file that’s located in the %systemdrive%\ProgramData\VMMLogs directory.

Note This log file may not exist if the failure occurs early in the installation process.

Step 2: Check the current winhttp proxy configuration

If winhttp is configured to use a proxy server (netsh winhttp set proxy), the attempts by VMM to communicate with managed servers through a fully qualified URL (for example, may fail unless Bypass proxy server for local address is defined to exclude FQDN host addresses. In this situation, error 2916 is returned. By using "<local>" alone, you'll bypass all short-name hosts. VMM uses FDQN. 

To check the current winhttp proxy configuration, run the netsh winhttp show proxy command. Additionally, the bypass list must be updated to include the domain name for hosts that are being added. For example, * will bypass the proxy for all hosts that end with ""

Example command:

netsh winhttp set proxy proxy-server="" bypass-list="*"

Step 3: Verify that the ports used by VMM are not blocked by a firewall

By default, VMM uses the following ports to communicate with the Hyper-V host:

TCP port 443
TCP port 5985
TCP port 5986

For more information about the ports that are used by VMM, see the following TechNet article:

Step 4: Check for duplicate SPNs

Perform the steps in the following article to check for duplicate SPNs:

970923 Unable to add a managed host in SCVMM 2008 and SCVMM 2012, Error 2927 (0x8033809d)

Step 5: Check for corrupted performance counters on the Hyper-V host

Check the Application log on the host to see if the following event is logged: 

Log Name: Application
Source: Microsoft-Windows-LoadPerf
Event ID: 3012
The performance strings in the Performance registry value is corrupted when process Performance extension counter provider. The BaseIndex value from the Performance registry is the first DWORD in the Data section, LastCounter value is the second DWORD in the Data section, and LastHelp value is the third DWORD in the Data section.

If the event ID 3012 is logged on the host machine, perform the steps in the following knowledge base article to rebuild the performance counters: 

2554336 How to manually rebuild Performance Counters for Windows Server 2008 64bit or Windows Server 2008 R2 systems

Step 6: Manually install the VMM Agent on the Hyper-V host

If the Add-SCVMHost job continues to fail, manually install the agent on the Hyper-V host by performing the steps in the following TechNet article: