title: Can't create handler inside thread that has not called Looper.prepare()
body: <p>What does the following exception mean; how can I fix it?</p>
  
  <p>This is the code:</p>
  
  <pre><code>Toast toast = Toast.makeText(mContext, "Something", Toast.LENGTH_SHORT);
  </code></pre>
  
  <p>This is the exception:</p>
  
  <pre class="lang-none prettyprint-override"><code>java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
       at android.os.Handler.&lt;init&gt;(Handler.java:121)
       at android.widget.Toast.&lt;init&gt;(Toast.java:68)
       at android.widget.Toast.makeText(Toast.java:231)
  </code></pre>