When there are over 30 downstream FortiGates in the Security Fabric, the root FortiGate's GUI may experience slowness when loading the Fabric Management page, preventing firmware upgrades using the GUI.Workaround: perform the firmware upgrade in the CLI. To perform the firmware upgrade using the GUI, temporarily disable the Security Fabric on the root FortiGate. When there are over 30 downstream FortiGates in the Security Fabric, the root FortiGate's GUI may experience slowness when loading the Fabric Management page and prevents the user from upgrading firmware in the GUI.Workaround: perform the firmware upgrade in the CLI. To perform the firmware upgrade using the GUI, temporarily disable the Security Fabric on the root FortiGate.