When NSX is uninstalled, the "Delete Compute Manager" step in the NSX UI unregisters the extension from vCenter. If the NSX Manager was deleted or formatted before this step, the vCenter Managed Object Browser (MOB) still contains the com.vmware.nsx.management.nsxt registration Case 36843893. This stale extension prevents the automated cleanup of NSX-managed network objects Unable to add compute manager.
Prerequisites:
https://<vCenter_FQDN>/mob/?moid=ExtensionManager.extensionList and identify com.vmware.nsx.management.nsxt Unable to add compute manager.com.vmware.nsx.management.nsxt in the extensionKey field and click Invoke Method Unable to add compute manager.If specific port groups remain after unregistering the extension:
dvs-id and dvportgroup-id for the stale segment from the browser URL when selected in the vSphere Client Remove Stale NSX Segments.https://<vCenter_FQDN>/mob/?moid=<dvs-id>&method=removeNsxPortgroups.dvportgroup-id in the parameters field and click Invoke Method Remove Stale NSX Segments.Restart the vSphere Client service via SSH to clear the inventory cache: