WAC720 Back to standalone

My English is very poor, this is translated by google. Please understand!
WAC720 requires Back To Standalone and runs multiple times in Console
Firmware-upgrade-tftp firmware.tar 192.168.1.200
The firmware can be successfully uploaded, but it is not always possible to switch back to standalone mode.
Can anyone help me? Thank you!

[root@Netgear /root]$ firmware-upgrade-tftp firmware.tar 192.168.1.200
Starting an Upgrade
*** Getting firmware file firmware.tar using tftp server 192.168.1.200 ***
killall: dhclient: no process killed
*** Getting firmware file firmware.tar using tftp server 192.168.1.200 done***

/bin/firmware-error-check: Validating upgrade.tar.
board_type not defined - allowing installation
-: OK
*** Bringing down Ethernet Interface ***
killall: syslog: no process killed
killall: snmpd: no process killed
killall: hostapd: no process killed
killall: telnetd: no process killed
killall: dhclient: no process killed
killall: udhcpc: no process killed
killall: nmbd: no process killed
killall: lighttpd: no process killed
killall: php: no process killed
killall: ntpd: no process killed
killall: klogd: no process killed
killall: sleep: no process killed
mkdir: cannot create directory '/lib/modules/2.6.15--LSDK-7.3.0.385': Read-only file system
killall: hostapd_app: no process killed
killall: hostapd_mgr: no process killed
killall: stats_mgr: no process killed
cp: cannot stat '/usr/bin/led-op': No such file or directory
cp: cannot stat '/lib/ld-uClibc-0.9.29.so': No such file or directory
cp: cannot stat '/lib/libcrypt-0.9.29.so': No such file or directory
cp: cannot stat '/lib/libm-0.9.29.so': No such file or directory
cp: cannot stat '/lib/libuClibc-0.9.29.so': No such file or directory