If you use the Oracle VM Server software that is preinstalled on your system, you must ensure that it is compatible with the version of Oracle VM Manager that you use to manage your Oracle VM infrastructure. If necessary to achieve compatibility, upgrade your Oracle VM Server or Oracle VM Manager so that they are the same version.
For information about upgrading the Oracle VM software, see the Oracle VM Installation and Upgrade Guide. The Oracle VM documentation is available at the following web site: https://www.oracle.com/technetwork/documentation/vm-096300.html