title: NReco HtmlToPdfConverter error: The specified executable is not a valid application for this OS platform
body: <p>I use NReco HtmlToPdfConverter and usually it works correctly. But sometimes I face with the following error: </p>
  
  <pre><code>Cannot generate PDF: The specified executable is not a valid application for this OS platform.
  </code></pre>
  
  <p>The code is quite simple, it is a singletone class: </p>
  
  <pre><code>public class Converter : IConverter
  {
      private readonly object lockObject = new object();
  
      public Converter()
      {
          HtmlToPdf = new HtmlToPdfConverter();
      }
  
      private HtmlToPdfConverter HtmlToPdf { get; }
  
      public byte[] GeneratePdf(string htmlContent)
      {
          lock (lockObject)
          {
              return HtmlToPdf.GeneratePdf(htmlContent);
          }
      }
  }
  </code></pre>
  
  <p>Does anybody know what can be a reason for such kind of error?</p>