title: Error: ORA-17008 - Closed Connection
body: <p>I try to run some PL/SQL on SQL Developer. It gives me an error although that same code works in SQL Plus. This error is always the same, whatever PL/SQL code I try with. </p>
  
  <p>What could be wrong?</p>
  
  <p><img src="https://i.stack.imgur.com/xGPYP.jpg" alt="enter image description here"></p>
  
  <pre><code>&lt;&lt;outer&gt;&gt;
  DECLARE
      xy varchar2(20);
  begin
      &lt;&lt;inner&gt;&gt;
      declare
          ww varchar2(20):='welcome';
      begin
          select ename into xy from emp where empno=7369;
          dbms_output.put_line(ww);
          dbms_output.put_line(xy);
      end;
  end;
  </code></pre>