Your PDF file may
be internally corrupted or may not be conforming to PDF encoding
specifications. Either it was created using a non-standard PDF creation product
(such as a scanner PDF creation driver), or the file has been damaged (for
example, it was sent as an email attachment and wasn't correctly decoded).
I would suggest that you try to "fix" the PDF by reprinting to PDF. To regenerate, you need to open the file in Adobe Acrobat, or a similar program that can print to PDF, such as our Sonic PDF Creator.
Open the file in Adobe reader and select File ---> Print ---> From your list of available printers please select one with PDF in the title, such as Sonic PDF. ---> Give the file a name ---> Click Print. After regenerating the PDF file, you can open it in the Able2Extract program. In certain cases, regenerating the PDF can fix certain errors in the PDF file - this may also be the case with your PDF file.
This article refers to Able2Doc, Able2Doc Professional, Able2Extract and Able2Extract Professional.