I have some documents where when I use the PDF to text functionality get a lot of question marks. Most documents work but I am leaving a link here to a zip file that both contains the PDF document I am trying to convert and the text. Please let me know what results you get.
http://neteject.com/download/VisualCron/pdftotext_badconvert.zip
Thanks for contacting support.
We were also able to observe similar issue at our side using Aspose.PDF for .NET 19.3. Hence, we have logged an issue as PDFNET-46173 in our issue tracking system for the sake of correction. As soon as there are some definite updates regarding issue rectification, we will share with you. Please be patient and spare us little time.
We are sorry for the inconvenience.