PDFs Will Not Open...

Beginning today, pdf's will not open on my Windows 10 PC. I try to open one, both attachments in emails and pdfs on my computer, but it just prompts me to login. I click ok and it just loops...nothing for a few seconds then the sign in page appears again. I've logged in to Creative Cloud, uninstalled and re-installed the program, restarted my computer a few times but nothing seems to work.