I ran into this issue today. We were deploying a vCenter appliance to a site with an external PSC. In the process we had an issue with name resolution and had to rerun the installation. While the vCenter inventory had been cleaned up by deleting the VCSA vm, the SSO directory still had an entry and needed to be cleaned up before we could successfully deploy the vCenter appliance.
Source: Attempting to join an Appliance-based Platform Services Controller or vCenter Server to a vSphere domain fails with the error: ERROR_TOO_MANY_NAMES (2114233) | VMware KB