Upgrading to the latest version
Under FortiGuard Firmware, select Latest. A notice may appear stating that there is no valid upgrade path for this firmware version. If this is the case, select All available instead and find a suitable firmware version for your FortiGate.
For more information about the upgrade path, go to Fortinet Support.
If no warning appears, select Release notes to learn more about the firmware build. Release notes are also available at the Fortinet Documentation Library.
To upgrade your FortiGate, select Backup config and upgrade. When prompted, select Continue.
Save the backup of your current FortiGate configuration, in case you need to restore it after the upgrade process.