Why can’t I open any attachent to email in the Windows Live Mail local client?

Up until recently, I could open every attachment that came with an email.  Now, in my inbox, I can see the paperclip indication that the email message has an attachment.  However, when I open the message, the attachment does not appear. I made certain that "Do not allow attachments to be saved or opened that could potentially be a virus" choice is not selected under Tools>Options>Security.  I disabled email protection in my anti-virus software.  I do not have a firewall.  I set Internet Explorer as my default browser.  Nothing worked.  Please help!  Thank you.