email attachments

I recently lost the ability to open attachments to email, both on a "remote"outlook, and at&t email center on their website. I can download attachments(office documents and pdf) on to hard drive and can open. however when trying to open attachments through Internet Explorer I get the message:'File could not be found. Try one of the following: Check spelling of file, try a different file name." This happened suddenly after a auto update. Does anyone have any ideas?

thanks