IndexOutOfRangeException may occur when getting PDF metadata

[clown]

When Metadata or Save button is pressed, IndexOutOfRangeException may occur.
From Stacktrace, there seems to be a problem in getting Title and other information from PDF metadata.
Any information on this matter would be appreciated.

Stacktrace is as follows:

PresentableBase (366) System.IndexOutOfRangeException
   iText.IO.Source.PdfTokenizer.DecodeStringContent(Byte[] content, Int32 from, Int32 to, Boolean hexWriting)
   iText.Kernel.Pdf.PdfString.DecodeContent()
   iText.Kernel.Pdf.PdfString.ToUnicodeString()
   iText.Kernel.Pdf.PdfDocumentInfo.GetTitle()
   Cube.Pdf.Itext.ReaderExtension.GetMetadata(PdfDocument src)
   Cube.Pdf.Itext.DocumentReader..ctor(String src, Password password, OpenOption options)
   Cube.Pdf.Editor.File.GetItext(Entity src, IQuery`1 query, Boolean partial)
   Cube.Pdf.Editor.SaveExtension.Save(MainFacade src, String dest, Action`1 prev, Action`1 next)
   Cube.Pdf.Editor.SaveExtension.<>c__DisplayClass3_0.<Overwrite>b__0()
   Cube.Syntax.Extensions.Methods.Then(Boolean value, Action action)
   Cube.PresentableBase.<>c__DisplayClass21_0.<Run>g__invoke|0()