Enabling AlwaysOn Availability Groups feature for a SQL Server Failover Instance must be run from the running primary node ...

Enabling AlwaysOn Availability Groups feature for a SQL Server Failover Instance must be run from the running primary node and the SQL Server Failover Cluster Instance must be running. Either run SQL Server Configuration Manager on the primary node, or start the SQL Server Failover Cluster Instance and try enabling AlwaysOn again.