You can also use /log for debugging.
If your firewall is on FortiOS 5.6 or 6.0, you can often upgrade to 6.4.10 (still receiving security patches). This allows you to use FortiClient 7.x, which is easily downloadable. forticlient version 6010 download link
These URLs will redirect to a login page unless you have session authentication. You can also use /log for debugging
: Log in to the Fortinet Customer Service & Support site. Navigate to Firmware : forticlient version 6010 download link