If you are getting the following message when accessing a website,
“Content was blocked because it was not signed by a valid security certificate”
You might want to check the followings:
1. Check the website certificate and make sure it is from the correct website.
2. Check your browser’s security settings and make sure it is correct.
3. Check your computer clock and make sure it is set correctly. A wrong settings will give this message. e.g. if you set in the time to something that is over the certificate date will give this error message too.