Cannot edit IPS signature default action

  Hi all. I can't edit IPS signature default action in FGT500D v5.2.3,build670 (GA) by GUI neither CLI.

CLI

FGT500D # config ips rule SSLv2.Get.Shared.Ciphers.Overflow
FGT500D (SSLv2.Get.Shared~low) # 
get Get dynamic and system information.
show Show configuration.
abort End and discard last config.
end End and save last config.

What i doing wrong?

Thanks