title: Abcpdf throwing System.ExecutionEngineException
body: <p>I have the binary for several pdf files stored in a collection of Byte arrays.</p>
  
  <p>My goal is to concatenate them into a single .pdf file using abcpdf, then stream that newly created file to the Response object on a page of an ASP.Net website.</p>
  
  <p>Had been doing it like this:</p>
  
  <p>BEGIN LOOP
  ...</p>
  
  <pre><code>'Create a new Doc
  Dim doc As Doc = New Doc
  
  'Read the binary of the current PDF
  doc.Read(bytes)
  
  'Append to the master merged PDF doc
  _mergedPDFDoc.Append(Doc)
  </code></pre>
  
  <p>END LOOP</p>
  
  <p>Which was working fine 95% of the time.  Every now and then however, creating a new Doc object would throw a System.ExecutionEngineException and crash the CLR.  It didn't seem to be related to a large number of pdfs (sometimes would happen w/ only 2), or with large sized pdfs.  It seemed almost completely random.</p>
  
  <p>This is a known bug in abcpdf described (not very well) here <a href="http://www.websupergoo.com/support.htm" rel="nofollow noreferrer">Item 6.24</a>.  I came across <a href="https://stackoverflow.com/questions/176113/every-now-and-then-abcpdf-runs-out-of-memory/176143#176143">a helpful SO post</a> which suggested using a Using block for the abcpdf Doc object.</p>
  
  <p>So now I'm doing this:</p>
  
  <pre><code>    Using doc As New Doc
          'Read the binary of the current PDF
          doc.Read(bytes)
          'Append to the master merged PDF doc
          _mergedPDFDoc.Append(doc)
      End Using
  </code></pre>
  
  <p>And I haven't seen the problem occur again yet, and have been pounding on a test version as best as I can to get it to.</p>
  
  <p>Has anyone had any similar experience with this error?  Did this fix it?</p>