All packages are not available for download error in android
<p><a href="http://i.stack.imgur.com/RAffF.png" rel="noreferrer">All packages are not available for download!</a>
  The following packages are not available:
- Package id sources;android-24</p>

<p>Am trying getting data from database by using of web services, when am running the application getting an above shown error.</p>

<p>How can I resolve this issue in the android studio?</p>