RB2011 kernel panic if run spectral-history while some clients connected

/system resource print
uptime: 1h50m23s
version: 6.37.1 (stable)
build-time: Sep/30/2016 10:28:41
free-memory: 97.2MiB
total-memory: 128.0MiB
cpu: MIPS 74Kc V4.12
cpu-count: 1
cpu-frequency: 600MHz
cpu-load: 12%
free-hdd-space: 109.0MiB
total-hdd-space: 128.0MiB
write-sect-since-reboot: 4599
write-sect-total: 30319766
bad-blocks: 0%
architecture-name: mipsbe
board-name: RB2011UAS-2HnD
platform: MikroTik
/log print where topics~“critical”
oct/06 19:24:34 system,error,critical System rebooted because of kernel failure
oct/06 19:24:34 system,error,critical router was rebooted without proper shutdown

Router rebooted immediately after issuing
/interface wireless spectral-history wlan1

There is a virtual interface in config

/interface wireless print
Flags: X - disabled, R - running
0 R name=“wlan1” mtu=1500 l2mtu=1600
arp=enabled interface-type=Atheros AR9300 mode=ap-bridge

1 name=“wlan2” mtu=1500 l2mtu=1600
arp=enabled interface-type=virtual master-interface=wlan1