I have the binary for several pdf files stored in a collection of Byte arrays.

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.

Had been doing it like this:

BEGIN LOOP ...

'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)

END LOOP

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.

This is a known bug in abcpdf described (not very well) here Item 6.24. I came across a helpful SO post which suggested using a Using block for the abcpdf Doc object.

So now I'm doing this:

    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

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.

Has anyone had any similar experience with this error? Did this fix it?