Removing Attachments from Contract record

Removing Attachments from Contract record

I'm updating a contract with a new pdf of the actual contract.  There is a pdf of the old contract in the Attachments list.  When I click that filename to download it, I get an error "The file was not found."  I want to delete that file name from the Attachment list.  I Edit the contract, click the red X next to the file name and it disappears.  However, when I Save the contract, the filename reappears again. It's as if the filename can't be deleted because the file it points do doesn't exist in the database for some reason