PDF greyed out and only shows content when you click on that section

Hi All,

I have been emailed a PDF, which opens fine! But all the information that has been added into the PDF does not show. All areas where writing has been added is blued out. However, when you click on each section where I know writing has been added, it will appear, only at the time of clicking on it. This sounds confusing and is hard to explain but I hope someone can help!
I have emailed this to other people to open up on different computers etc but it still does the same thing. Can someone please help. This is a very important university document. Thanks!