Problem: eBook does not download and "Failed to load PDF document" is displayed. This tends to happen when using the Chrome browser only. The Download function should work with Firefox and Internet Explorer.

Solution: Try opening the file from the computer's downloads file (File Explorer- This PC- Downloads) Then right click on the PDF, go to 'open with' and select Adobe. This should allow you to open it.

Extra:

To set Adobe as the default program for opening PDFs (listed by Chrome version):

• Version 60 onwards: Go to Windows File Explorer, find any PDF file and right click. Select ‘Open with’, and ‘Choose another app’. Set it to Adobe Reader as default and tick ‘Always use this app to open .pdf files’.
• Versions 57-59: Go to the Options bar (below) 
• Click ‘Settings’, and ‘Show advanced settings’. Then, under the privacy heading, click on ‘Content settings’. Scroll down to ‘PDF Documents’ and uncheck the box for ‘Open PDF files in the default PDF viewer application’
• Version 56 or below: Enter ‘about:plugins’ in the address bar, scroll down to 'Chrome PDF Viewer' then click 'Disable'.