At my day job that shall not be named I use a Fortigate 60C at one of the sites I maintain. The other day I noticed that the SSL certificate for it expired, and when I went into the web UI for the unit I couldn't find the section to manage certificates. If you are new to Fortigate that is usually located in System > Certificates.
Here is what it looked like:
Fortigate# config system global
Fortigate (global)# set gui-certificate enable
Fortigate (global)# end