You might see this warning when you visit a site that has you connected to with an HTTPS connection: This site is using outdated security settings that may prevent future versions of Chrome from being able to safely access it.
This alert/error means that the website is using an old security algorithm such as SHA-1 (as perfectly explained by Eric Mill in this blogpost), which is potentially no longer safe. Google is actually trying to kill SHA-1 on the web, as explained in their blogpost on “Gradually sunsetting SHA-1”
By 2017, the Google Chrome browser will even show a red warning for websites that use the SHA-1 algorithm for their certificate.
Test your SSL certificate at SSLLabs. This test will give you plenty of details about your certificate and what you can do to improve its security.