I use gmail for my email. I received an email today that had a pdf attachment. I don't know about my PDF app, I see the word "Lumin" next to the open with, when I click Lumin, it takes me to a request for permission site. I've uploaded what I see below. When I open the attachment I see the image with a black background with the choices i get are open or "open with". How do I know what the default reader app is or if I've changed it somehow. Again, thanks. sorry for being all over trying to answer the question.