PDF Ocr with IronOcr throws SEHException when running read

        var ocr = new IronOcr.IronTesseract();
        using (var input = new IronOcr.OcrInput( ) )
        {
            input.AddPdfPages( "./20160026957.pdf", new[] { 1 } );
            input.Deskew();
            //input.DeNoise();
            var contents = ocr.Read( input );
            Console.Write( contents.Text );
        }

ocr.Read() throws an SEHException. The stack trace is as follows:

Fatal error. System.Runtime.InteropServices.SEHException (0x80004005): External component has thrown an exception.
   at IronOcr.Extensions.scotjg.xqdvnf(System.Runtime.InteropServices.HandleRef, System.Runtime.InteropServices.HandleRef)
   at IronOcr.Extensions.scotjh.qjuwqn(System.Runtime.InteropServices.HandleRef, System.Runtime.InteropServices.HandleRef)
   at IronOcr.Extensions.scotji.pykdtk()
   at IronOcr.Extensions.scotjz.hmqdoj(IronOcr.Extensions.scotji)
   at IronOcr.IronTesseract.mwlewb(IronOcr.OcrResult, IronOcr.Extensions.scotkf, System.Collections.Generic.IEnumerable`1<IronOcr.Extensions.scotjz>, imgsra, Int32)
   at IronOcr.IronTesseract.mwlewb(IronOcr.OcrInput, System.Nullable`1<System.Drawing.Rectangle>)
   at IronOcr.IronTesseract.Read(IronOcr.OcrInput)
   at Preprocessing.Program+<Main>d__0.MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.__Canon ByRef)
   at System.Runtime.CompilerServices.AsyncTaskMethodBuilder.Start[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.__Canon ByRef)
   at Preprocessing.Program.Main(System.String[])
   at Preprocessing.Program.<Main>(System.String[])

Can anyone provide any guidance?