vsphere-ui log says
http://.zip .Make sure it is a valid zip file then logout/login to force another download. java.util.zip.ZipException: zip file is empty
The zip file is not available at /etc/vmware/vsphere-ui/vc-packages/vsphere-client-serenity.
where as it is available at /etc/vmware/vsphere-client/vc-packages/vsphere-client-serenity.
I have added allowHttp = true in webclient.properties under /etc/vmware/vsphere-client.