Exchange 2013 CU2 Error: Windows Failover Clustering isn't installed

I installed two Mailbox Servers and created a DAG. No problems adding first server to DAG.

 

However, got an error while adding second server to DAG:

 

A server-side database availability group administrative operation failed. Error The operation failed. CreateCluster errors may result from incorrectly configured static addresses. Error: Windows Failover Clustering isn't installed on 'ex2013-server'

I got this error from both EAC and EMS. Actually, Windows Failover Clustering should be automatically installed when adding a DAG member.

Solution:

1. Windows PowerShell: install-windowsfeature failover-clustering
2. Add second DAG member again