Adobe Acrobat Reader DC - Nothing Happens

Hi,

When I double click a pdf, the program opens but nothing else happens. I can't view the file and when I hit "show all windows", everything zooms out and I see the file name of the file I was trying to open, but not a small thumbnail of it like I remember seeing. I'm using a 2015 Macbook pro, and the latest version of Adobe Acrobat Reader DC. Just updated it and reinstalled it, and it is still happening. Any ideas?

Thanks!