vCenter Server registration fails with the error: Extension already registered

Products

• VMware NSX Networking
• VMware vCenter Server

Issue/Introduction

Symptoms:
On an NSX MP UI/API, you see these symptoms:

• The vCenter Server registration fails.
• You see this error:
  
  Extension already registered

• You see the error similar to:
  
  Compute manager <UUID1> registration failed with server 192.168.x.182 due to issue Error in rest call. url= //cm-inventory/api/v1/cm-plugin-container/cm-plugins?action=register , method= POST , response= { "httpStatus" : "BAD_REQUEST", "error_code" : 40110, "module_name" : "cm-inventory", "error_message" : "Extension already registered at 192.168.x.182 with id <UUID1>" } , error= 400 Bad Request .

Cause

This issue occurs when a vCenter Server is already registered on one NSX Manager, and you attempt to register the same vCenter Server to another NSX Manager.

Resolution

This issue is resolved in VMware NSX-T 2.0.0.

To work around this issue, remove the com.vmware.nsx.management.nsxt extension.

1. Log in to this URL https://VC_FQDN/mob/?moid=ExtensionManager as a vCenter Server Administrator.
2. Use the UnregisterExtension to remove the com.vmware.nsx.management.nsxt extension.