title: PdfWriter.GetInstance throws System.NullReferenceException
body: <p>I'm trying to create a pdf document using iTextSharp 5.3.4 using the following</p>
  
  <pre><code>Document document = new Document();
  FileStream stm = new FileStream(filename, FileMode.Create);
  PdfWriter writer = PdfWriter.GetInstance(document, stm);
  </code></pre>
  
  <p>I'm getting a System.NullReferenceException with the following stack trace:</p>
  
  <pre><code>System.NullReferenceException occurred
  HResult=-2147467261
  Message=La référence d'objet n'est pas définie à une instance d'un objet.
  Source=itextsharp
  StackTrace:
     à iTextSharp.text.Version.GetInstance()
  InnerException: 
  </code></pre>
  
  <p>I've verified that neither document nor stm are null, and if I select "continue" in VS12 the document is created - however the exception is always thrown.
  I updated to iTextSharp 5.4.0 and it's still occurring.
  I can't find any information on this anywhere - anyone got any ideas?</p>