No android device found in unity
<p>When I am building a game for android, I get this message:</p>

<blockquote>
  <p>No Android device found!
  Make sure USB debugging has been enabled.
  Check your device. In most cases there should be a small icon in the status bar telling you if the USB connection is available.
  If you are sure that your device is attached then it might be your USB driver that's the problem. For details please check the Android SDK setup section in the Unity manual.</p>
</blockquote>

<p>The cancel windows showed this error:</p>

<blockquote>
  <p>No android device found! If you are sure that your device is attached then it might be your USB driver that's the problem. For details please check the Android SDK setup section in the Unity manual.</p>
</blockquote>

<p>The same error also appeared in the Console.
How do I fix this error?</p>

<p><a href="https://forum.unity3d.com/attachments/2016-04-14_14-00-52-png.181659/" rel="noreferrer"><img src="https://forum.unity3d.com/attachments/2016-04-14_14-00-52-png.181659/" alt=""></a></p>