When clicking on a link to a PDF within your course, all pages within that document should have content. Recently, we've received reports from some users that some/all pages within that document are blank or have not loaded.
If this issue comes up, specifically for PDFs with larger file sizes, please make sure you're downloading the PDF to your system first (right-click the link, "Save link as..." or similar) instead of relying on your internet browser to view the PDF. In some cases, the PDF viewer within your browser does not show all pages even though it should. After downloading the file, you can then view the full document.