Disable Ssl Scanning When Using Mozilla Firefox

Hello,

I'm using Bitdefender Internet Security 2015 Version 19.6.0.326 and Firefox 45.0.

I am getting the following message for most of the web pages when SSL scanning is ON:

"Your connection is not secure

The owner of www.youtube.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website.

This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox only connect to it securely. As a result, it is not possible to add an exception for this certificate.

Learn more…"

I don't have this issue with Google Chrome and I haven't had this problem with Mozilla until today. Don't know which got updated or what else caused the problem.

I saw that it is not an unknown issue on the web and it was encountered before. So why did it occurred again?