title: main cannot be resolved or is not a field
body: <p>This error occurs in setContentView line in this code snippet:</p>
  
  <pre><code>/** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
  </code></pre>
  
  <p>I understand that in order for R.layout.main to be resolved, a file named <strong>res/layout/main.xml</strong> must be present.</p>
  
  <p>It is present and valid (i.e. Eclipse marks it as perfect without any errors). So, what else could cause this error?</p>
  
  <p>BTW, I already tried Project > Clean. The error persists.</p>