firewall lost connection

[noc2]

I have fortigate 100D with 5.0.9. firewall loose the connection with LAN device.

It's happened again and again in 20 mint.

I attached the log of during firewall lost the connection with my LAN.

[Dave_Hall]

The screenshot shows a Fortigate typically starting or booting up and not much else.  You may be better off connecting a console (rollover) cable to the console port and use putty to monitor the Fortigate's active.  If the Fortigate is rebooting, you should see the cause or warnings on the console.   What does the system resources widget show for CPU, memory and disk usage?