title: Netbeans refuses to auto suggest known classes for imports
body: <p>I just discovered that my NetBeans suddenly stops importing classes that are found in the Java API but can still import classes from my external libraries. Take a look at the image below: </p>
  
  <p><img src="https://i.stack.imgur.com/7yd1w.jpg" alt="NetBeans editor"></p>
  
  <p>As you can see, <code>List</code> and <code>ArrayList</code> are classes from the <code>java.util</code> package but the usual suggestions for importing them are not shown here, instead it is asking me to create class. I know that I can type <code>import java.util.List;</code> on the top of the code but life was better before! Please I need help thanks.</p>