Dear Customer, Hope you are doing good. It seems you are trying to migrate fortigate 501f to 601f. Please be informed that for the backup configuration to work on other device, it should be of same hardware model and same fortios version running on. As both 501F and 601F fortigate are different hardware model, so you need to manually configure the new 601F or you can take help for the forticonvertor tool and proceed with the migration.
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