Hello, I am trying to download Adobe Acrobat Reader on quite literally any browser on my Mac computer. Every time I click to install the program a message pops up saying "Only a single copy of the installer can run at a time. Please close the other window and try again." Why is this message popping up, and how can I successfully download Reader? I have no other windows or installers open, so I have no idea what is going on. Of course when I called Adobe to get help they told me nobody is trained to solve issues like this, which is absolutely ridiculous. I need this application for work and am beyond annoyed that it will not function nor that anyone seems to be willing to help. I would appreciate immediate assistance.