hostd crashed with a core file created. This might have caused connections to the host to be dropped.
The host daemon process on the host has crashed and generated a core dump file for further analysis.
See the event description for more detailed information specific to this event. Further information can be found in the VMware KB article Hostd uses a lot of CPU or has generated a core dump.
Refer to the VMware Online Documentation for more information on vCenter event messages and possible solutions.