Configuration issues and other errors can occur for your cluster or its hosts that adversely affect the proper operation of vSphere HA. You can monitor these errors by looking at the Cluster Operational Status screen, which is accessible in the vSphere Client from the vSphere HA section of the cluster’s Summary tab. Address issues listed here.
Most configuration issues have a matching event that is logged. All vSphere HA events include “vSphere HA” in the description. You can search for this term to find the corresponding events.