Same problem here with a 60D with ipsengine crashing many times a day :
type=event subtype=system level=warning vd="root" logdesc="Application crashed" action=crash msg="Pid: 02321, application: ipsengine 03.170, Firmware: FortiGate-60D v5.2.9,build0736b736,160907 (GA) (Release), Signal 11 received, Backtrace: [0x30d9cb58] [0x30d9790c] [0x30d9ce08] [0x30d86594] [0x30c8cf34] [0x30c9eb28] [0x30c69d3c] [0x008aff60] [0x008b1d98] [0x008b34e0] [0x00039938] [0x008b3980] [0x008b4944] [0x00039938] [0x000393ac] [0x00037450] [0x00038f8c] [0x000368bc] [0x300e3bc4]"
From what I see in this post, my ips engien is rather old. Should an update solve this problem ?
If I downgrade to 5.2.8, can you confirm this should also sovled this problem ?