Error: 'Failed to unregister vCenter Server "VC_NAME". Real networks from this vCenter Server are still referenced' while unregistering the vCenter from VMware Cloud Director

Products

• VMware Cloud Director

Issue/Introduction

• Unable to unregister vCenter in VMware Cloud Director (VCD) UI. When you try to unregister the vCenter from VCD you see the below error:
  
  [ ######-##-##-##-###### ] Failed to unregister vCenter Server "######". Real networks from this vCenter Server are still referenced. - Failed to unregister vCenter Server "######". Real networks from this vCenter Server are still referenced.
  
  
• You might see the below errors too while unregistering vCenter Server from VCD UI:
  
  [ ########-####-####-####-####2d3b ] Cannot unregister shield manager because network pools are still backed by it: <Name of the Network Pool> [########-####-####-####-####a214]
  
  
• This solution covers the scenario where you simply want to unregister this vCenter server and remove all its resources from VCD. For the scenario of migrating all resources to a replacement vCenter, please see KB# 397667

Environment

• VMware Cloud Director 10.5.x 
• VMware Cloud Director 10.6.x

Cause

This issue can occur when there are references to this vCenter remaining in the real_network and real_network_backing tables in the Cloud Director database.

Resolution

To resolve the issue please remove any entities that is linked to the vCenter instance. If there are particular networks mentioned in the error message, please:

• Remove network resources which are linked to this vCenter through the Cloud Director UI:
  • vApps
  • Network pools
  • References to the vCenter in External Networks
• Remove any leftover network resources which relate to networks in VCD in vCenter:
  • Logical networks
  • Port groups

With this complete, try unregistering the vCenter from VCD UI once again.

If this is not sufficient or you are facing further errors, please contact Broadcom Support and note this Article ID (404252) in the problem description. For more information, see Creating and managing Broadcom support cases.