can't follow link


For some reason I no longer am able to follow links in my e-mails.
Whenever I click on a link I receive the message, "Application Not Found."
Tried pursuing Help instructions that I was to click the Information Bar and
click on "Unblock." That option is not on my Information Bar.
I looked at Security Options and don't see any relevant options. My setting is on low.
I have Norton Security.

Any help would be appreciated.
Dwight Delahunt