This error usually appears when the whole PDF file is selected for the conversion and the file itself is either huge or complicated (by its content).
To correct the error, please try one of the two solutions:
1. option: Do the conversion in several turns, by using the "Select Page Range" option from the Edit menu. In other words, instead of using the "Select All" option, select one half, or one third of the pages from the PDF file and convert that part of the file.
When you have finished this, do the same with the rest of the pages.
2. option: Break the document up into smaller parts prior to importing it into Able2Extract.
This article refers to Able2Extract and Able2Extract Professional.