After certificate expiration the provider and tenant portals will still load. When navigating through the UI there will be no resources, certificates, vCenters, or organizations returned. Pages that would normally be populated will be blank.
API calls will still return resources.
There are no errors in the UI.
VMware Cloud Director 10.5.1
There is certificate expiration for one of the Cloud Director sites, and this is a multi-site deployment.
Delete the multi-site configuration: