title: Could not proceed due to error in ExpanableListAdapter
body: <p>I'm trying this code and found this error:</p>
  
  <p><a href="https://i.stack.imgur.com/paXYq.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/paXYq.jpg" alt="enter image description here"></a></p>
  
  <p>I don't know the reason. </p>
  
  <p>If anyone knows it kindly help me.</p>