Your SSL certificate is either missing or needs renewed. Any web browser is going to warn people about viewing this site because it does not have an SSL. You can get a free SSL certificate at SSL for Free, you just have to update it every 90 days. Even though this is not an eCommerce site, users can be in danger by being redirected to dangerous sites. Web sites without SSL can have page overlays or pop-ups added to the site from outside hackers. SSL is now common for all sites.