DescriptionFortiOS will not accept the upload to a FortiGate unit of an AV definition or IPS definition/engine that is older than the one which is currently installed on the unit.
The error message "Firewall has all the updates found in the given file" will be reported. ScopeFortiOS versions 4.00 MR3, 5.0.x, 5.2.x and 5.4.xSolutionThe downgrade procedure is as follows:
1. From the FortiGate CLI, launch the command:
# diagnose autoupdate downgrade enable
2. From the FortiGate GUI, import the AV definition, IPS definition/engine needed.
3. From the FortiGate CLI, launch the command:
# diagnose autoupdate downgrade disable
4. Verify if the downgrade process is fine from CLI:
# diagnose autoupdate versions
5. If necessary, disable scheduled updates from FortiGuard Distribution Network to keep imported signatures/prevent automatic updates:
# config system autoupdate schedule
# set status disable
# end