Warning: USING OUT OF TREE BOARD

I deleted nrf-related files and set up nrf programs from a scratch following Get Started Assistant of nRF Connect v3.0.0

I've got this warning when I opened a project by "Open nRF Connect SDK Project".

SEGGER Embedded Studio v.4.18

How can I solve this?

Zephyr version: 1.14.99
USING OUT OF TREE BOARD
nrf9160_pca10090ns.dts.pre.tmp:269.19-275.3: Warning (unique_unit_address_if_enabled): /soc/peripheral@40000000/clock@5000: duplicate unit-address (also used in node /soc/peripheral@40000000/power@5000)

warning: MQTT_LIB_TLS (defined at subsys/net/lib/mqtt/Kconfig:30) was assigned the value 'y' but got
the value 'n'. You can check symbol information (including dependencies) in the 'menuconfig'
interface (see the Application Development Primer section of the manual), or in the Kconfig
reference at http://docs.zephyrproject.org/latest/reference/kconfig/CONFIG_MQTT_LIB_TLS.html (which
is updated regularly from the master branch). See the 'Setting configuration values' section of the
Board Porting Guide as well.

/Users/fukuharayuusuke/Documents/nRF9160/ncs/nrf/applications/asset_tracker/prj.conf:13: warning: attempt to assign the value 'y' to the undefined symbol MQTT_SOCKET_LIB

/Users/fukuharayuusuke/Documents/nRF9160/ncs/nrf/applications/asset_tracker/prj.conf:15: warning: attempt to assign the value '2048' to the undefined symbol MQTT_MAX_PACKET_LENGTH

/Users/fukuharayuusuke/Documents/nRF9160/ncs/nrf/applications/asset_tracker/prj.conf:19: warning: attempt to assign the value 'y' to the undefined symbol LTE_LINK_CONTROL

/Users/fukuharayuusuke/Documents/nRF9160/ncs/nrf/applications/asset_tracker/prj.conf:20: warning: attempt to assign the value 'n' to the undefined symbol LTE_AUTO_INIT_AND_CONNECT

/Users/fukuharayuusuke/Documents/nRF9160/ncs/nrf/applications/asset_tracker/prj.conf:23: warning: attempt to assign the value 'y' to the undefined symbol MODEM_INFO

/Users/fukuharayuusuke/Documents/nRF9160/ncs/nrf/applications/asset_tracker/prj.conf:26: warning: attempt to assign the value 'y' to the undefined symbol BSD_LIBRARY

/Users/fukuharayuusuke/Documents/nRF9160/ncs/nrf/applications/asset_tracker/prj.conf:29: warning: attempt to assign the value 'y' to the undefined symbol NRF_CLOUD

/Users/fukuharayuusuke/Documents/nRF9160/ncs/nrf/applications/asset_tracker/prj.conf:36: warning: attempt to assign the value 'y' to the undefined symbol DK_LIBRARY

/Users/fukuharayuusuke/Documents/nRF9160/ncs/nrf/applications/asset_tracker/prj.conf:37: warning: attempt to assign the value 'n' to the undefined symbol DK_LIBRARY_INVERT_LEDS

/Users/fukuharayuusuke/Documents/nRF9160/ncs/nrf/applications/asset_tracker/prj.conf:50: warning: attempt to assign the value '1024' to the undefined symbol GPS_SIM_THREAD_STACK_SIZE

Error: Aborting due to non-whitelisted Kconfig warning
'/Users/fukuharayuusuke/Documents/nRF9160/ncs/nrf/applications/asset_tracker/prj.conf:13: warning:
attempt to assign the value 'y' to the undefined symbol MQTT_SOCKET_LIB'. Note: If this warning
doesn't point to an actual problem, you can add it to the whitelist at the top of
/Users/fukuharayuusuke/Documents/nRF9160/ncs/zephyr/scripts/kconfig/kconfig.py.

CMake Error at /Users/fukuharayuusuke/Documents/nRF9160/ncs/zephyr/cmake/kconfig.cmake:200 (message):
  command failed with return code: 1
Call Stack (most recent call first):
  /Users/fukuharayuusuke/Documents/nRF9160/ncs/zephyr/cmake/app/boilerplate.cmake:529 (include)
  CMakeLists.txt:11 (include)


When I use SEGGER Embedded Studio v.4.16, there is no error.