I have the same problem which is addressed here https://communities.vmware.com/docs/DOC-28682?z=BYJ9FY
Though in this case, it doesn't show up in the /mob nor it doesn't tell anything specific about failing in the vcenter logs. My vcenter is an appliance (newest 5.5 version, updated today).
Openstack is mentioned in the vcenter only on these places:
find / -xdev -type f -print0 | xargs -0 grep -H "openstack"
Binary file /usr/lib/vmware-vpx/sps/resources/cachedb/sms-cache0.h2.db matches
Binary file /usr/lib/vmware-vpx/sps/resources/cachedb/sms-cache1.h2.db matches
/etc/services:openstack-id 35357/tcp # OpenStack ID Service [Rackspace_Hosting] [Ziad_Sawalha]
ESXi host is also running newest 5.5. VIO management server appliance boots up ok (though it sets up localhost.localdom system name, and there's fqdn + reverse configured during the installation)
Management server reboot doesn't solve the issue, neither does reloggin from web client. Both vcenter and management server are in the same private subnet ( /24) and can ssh to each other.