This step is required only if you use a customer-specified certificate. The server data migration process does not migrate customer-supplied certificates from the vCloud Application Director 6.0.1 server. The new Application Services 6.1 server likely has a different IP address or hostname than its predecessor. If a certificate was generated with either property, it does not apply to the Application Services 6.1 server. You need to recreate the certificates and apply them to the Application Services 6.1 server.

Create certificates for the Application Services 6.1 server and apply them as described in the VMware knowledge base article at http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2065009.