Norton Sec wont allow PDF and Tiff

Hi,

I use Mozilla Thunderbird email client, locally on my Computer, and Norton Security 2015. With Norton Security Smart firewall, I can neither "open" or "save as" locally any PDF or Tiff image file attachements. I can see they are there in my email I recieve, but not do anything with them. But if I temporary turn off the Smart fiewall, it suddenly allow PDF and tiff file attachments to be open and viewed and saved to any folder locally on my computer. My workaround, currently, because I like to have my firewall ON for obvious reasons... I have to go to my webmail in my web browser instead and "save as" to my computer.

Any solutions, settings to stop Norton Security from doing this? I have looked but not found any solution

Thank you
Stefan