The AlwaysOn feature must be enabled for the server instance {0}' before you can create an availability group on this instance. ...

The AlwaysOn feature must be enabled for the server instance ‘{0}' before you can create an availability group on this instance. To enable AlwaysOn, open the SQL Server Configuration Manager, select SQL Server Services, right-click the SQL Server instance name, select Properties, and use the AlwaysOn High Availability tab of the SQL Server Properties dialog.