Website displaying as "Not Secure" and not displaying graphics or images
On Chrome when I try to open certain websites, it displays as "Not Secure" and doesn't display any graphics or images, but instead a menu-like black and white display/menu.
All certificates are valid for the sites. I have tried clearing history (etc.). On Safari it's even worse as it doesn't let me even open the website.
iMac 21.5″, OS X 10.11