digital additions

I am a writer.  I have downloaded digital additions at least ten times trying to get it to function.  All I have been able to do so far is upload my book, and see the cover.  When I try to see any of the pages and read my book for editing errors, I can see the numbers moving on the slide bar, but the pages will not appear.  I can click on the table of contents and see the numerical slide bar move, but the pages will not appear.  I have been the route of making sure my computer has permission, but I cannot get anything to work.  It is almost like everything is frozen.  I have tried all I know to do, can anyone help?