Here’s a good tip in case you ever want to reinstall System Center Virtual Machine Manager (SCVMM). If you use the "Retain Data" option you will likely be unable to create Virtual Machines if the same build of SCVMM is re-installed.
If you try to create a Virtual Machine on a host after the reinstallation, this error is encountered:
An internal error has occurred trying to contact an agent on the ContosoHost.Costoso.lab server.
(Element not found (0x80070490))
The reason this can occur is because the certificate is removed from the Host during the removal of SCVMM. A re-installation of the same build of SCVMM does not replace the certificate and it is therefore not added back into the certificate store on the SCVMM server.
To resolve this issue, the Host must be removed from SCVMM and then re-added as a Host.