There is a possibility this issue is related to new security requirements put on eCommerce providers like us by the banking industry. We recently were required to upgrade our web store security requirements. 

This change essentially means those who wish to access our eCommerce site must use a modern and secure browser.

If the problem is related to an older version of Microsoft Internet Explorer, this might be a fix. This will work for Internet Explorer versions 8 through 10.

Go to:    Settings -> Internet Options -> Advanced tab and enable “Use TLS 1.1” and “Use TLS 1.2” under the security section (see images below). 

As you can see these are security related configurations; it is important to use a secure browser when “traveling on the Internet” just like having a secure/ safe car when on the freeway.  

Here is a list of supported browsers:               Click Here for more