Unable to Connect Hyper-V Host via WMI. User credentials cannot be used for local connections.

When trying to add a Hyper-V host, you receive the error "Unable to connect via WMI. User Credentials cannot be used for local connections."

Not all of the prerequisites have been installed when using Veeam Backup & Replication.  

Before adding Hyper-V servers, check the following prerequisites:

1. Make sure the SCVMM Admin UI is installed on the Veeam Backup & Replication server. Otherwise, you will not be able to add SCVMM servers to Veeam Backup & Replication. 
2. On every connected Hyper-V server, Veeam Backup & Replication deploys a set of components – Veeam Installer Service, Veeam Transport Service and Hyper-V Integration Service. Ensure that File and Printer Sharing is enabled in the network connection settings of the server; otherwise, the components will not be installed.

This only occurs in version 6 of Veeam Backup & Replication.  

Also, how to install the SCVMM Admin UI from Microsoft is available here:
http://technet.microsoft.com/en-us/library/bb740758.aspx