Assume that the ExternalURL property for the Exchange Control Panel (ECP) virtual directory is not set in a Microsoft Exchange Server 2013 environment. In this situation, the Autodiscover.Protocol health set is unhealthy, and the AutodiscoverSelfTestProbe probe fails together with the following event:
To resolve this issue, install the following cumulative update:
2961810 Cumulative Update 6 for Exchange Server 2013
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about the Autodiscover.Protocol health set, go to the following Microsoft website: