Running Play 2.4.x Locally Yields: java.lang.IllegalArgumentException: port out of range:-1
<p>While trying to start my Play app locally I am getting a </p>

<blockquote>
  <p>java.lang.IllegalArgumentException: port out of range:-1</p>
</blockquote>

<p>exception followed by a </p>

<blockquote>
  <p>(*:playRun) java.lang.reflect.InvocationTargetException</p>
</blockquote>

<p>message.  I can see in the trace the invalid port arg being sent <code>(..../Scala/launcher/sbt-launch.jar" xsbt.boot.Boot "~run -1")</code> but cannot find where to update this argument.  There has to be somewhere to override default values.  And...  No matter what is in the application.conf (http.port) or what I pass on the command line -Dhttp.port I still get the same error.  Any info would be enormously appreciated.  </p>