title: The activity 'MainActivity' is not declared in AndroidManifest.xml
body: <p>I am getting an error which reads <strong>The activity 'MainActivity' is not declared in AndroidManifest.xml</strong></p>
  
  <p><img src="https://i.stack.imgur.com/jcPrp.png" alt="Screenshot of the error"></p>
  
  <p>What is the problem here?</p>