Restart the FortiGate. When prompted, press any key to enter the boot menu. Select the option to .
execute restore image url https://example.com fortigate firmware download install
FortiGate configurations are stored in a binary format. When the device reboots with new firmware, a script runs to convert the old configuration syntax to the new syntax. This is why . If the conversion script encounters a syntax it can't handle (often due to deprecated features), the device might default to factory settings to preserve network reachability. Restart the FortiGate
Navigate to (or System > Fabric Management in newer versions). Click Browse or Upload Firmware . Select the .out file you downloaded. execute restore image url https://example
If your device has an active FortiCare contract and internet access, you can do this directly from the firewall.