cu_acd crash in FGT 5.6.5 after managed FortiSwitch 3.5.7 ports settings changed in GUI

Hi all,

I just got a crash report for cu_acd on my FortiGate 100D 5.6.5 after making a few simple modifications to its managed FortiSwitch 124E-POE 3.6.7 from the FortiGate GUI (setting a couple vlans on ports, turning off BPDU Guard for one).

No previous crashes reported.  I had recently shutdown the switch, moved it, and reconnected, but it had been running for an hour or so without problems.

Any idea what cu_acd is, and why it might have crashed?

3225: 2018-08-28 09:12:16 <00204> application cu_acd 3226: 2018-08-28 09:12:16 <00204> *** signal 6 (Aborted) received ***