This issue occurs when vCenter Server is installed on a machine other than the one used for the original install, but is referencing the same vCenter Server database as the original install.
For example, you install or upgrade to vCenter Server 5.0 on a machine and use a remote vCenter Server database. You then uninstall vCenter Server, reinstall vCenter Server on a new machine, and use the same database instance.
This issue may occur because of erroneous endpoint information in vCenter Server for the Inventory Service.
Note: This issue has also been reported to occur after changing the vCenter Server hostname