Clicking on a PDF opens the application but not the document

After installing Reader in Windows 10, I followed the popup window's directions for making the program the default for PDFs. But the window doesn't go away until I click the close button at the top. And now the PDFs have the Reader program icon and not the PDF document icon, and when I click on one of them, the program opens but the PDF doesn't load. I can view the document by opening it from Reader's File menu, but