title: Pluggable database does not exist
body: <p>I have Been Working with <code>Oracle sql developer</code> almost for a year now, I have many users created including HR.
  Earlier today I've connected to my pluggable database and things went fine.
  Now when I write in the <code>CMD</code>:</p>
  <pre><code>ALTER SESSION SET CONTAINER = PDBORCL;
  </code></pre>
  <p>It says: <code>ORA-65011: Pluggable database PDBORCL does not exist.</code>
  But it absolutely exists! Because I've been working with it so many times.
  Any thoughts are appreciated.</p>