If you have a legitimate physical copy of the Allen module, simply scan it yourself using a mobile scanner (Adobe Scan or Microsoft Lens) at 300 DPI. This creates a "perfect" PDF from a physical source, bypassing all digital corruption issues forever.
Try converting the PDF to a Word document and back to PDF to reset the file structure. allen biology modules pdf fix
You know you need an "Allen Biology modules PDF fix" when you observe: If you have a legitimate physical copy of