unable to open pdf in safari.

I'm trying to access a series of PDF files from a website.

I get the message "The document you are trying to load requires Adobe Reader 8 or higher........"

I downloaded the latest version of Adobe Reader DC. However, I still have the same problem.

I am able to download the file and open it from my hard drive using Adobe Reader DC.

When I attempt to attach the files to an email I get the same error message.

Can anyone help ?