FAQ: Why is my web application down?

The SSL certificate on your server expiring is the common cause of this behavior. 

The SSL certificate handles the security of the website, and if it is expired it can cause the website authentication to not go through. 

The SSL certificate is/was not managed, or implemented, by End2End and is the responsibility of the department to ensure that the certificate stays up-to-date and valid. 

To solve this behavior a new certificate must be procured and bound.