The download may not have completed and connection has been lost.
Open Adobe Digital Editions (ADE) and check to see if the book is appearing. Click on it to open. It may restart the download process, this may take some time. Be patient.
If you cannot see the book when you open your ADE library, choose File > Add to Library > browse your computer to search and select the .acm file to reconnect and finish the download.
Alternatively, you could download using the University WiFi on campus or simply choose the ‘Read Online' option.