STRING_AGG is not a recognized built-in function name
<p>I've downloaded and installed SQL Server 2016. When I attempted to use the <code>STRING_AGG</code> function I receive this error. Here is my code:</p>

<pre><code>SELECT STRING_AGG(cast(FieldNumber AS VARCHAR(100)), ',')
FROM Fields
</code></pre>

<p>I've installed SQL Server 2016 and SP1. Is there anything else I need to do. Here is the feature I am trying to use. <a href="https://msdn.microsoft.com/en-us/library/mt790580.aspx" rel="noreferrer">String Agg</a></p>