wlan0:INTERFACE-DISABLED

[wwdok]

After i run python3 createap.py on raspberry pi, the command prompt output :

hostapd: no process found
Config dir: /tmp/create_ap.wlan0.conf.P4mV3lTx
PID: 15341
No Internet sharing
hostapd command-line interface: hostapd_cli -p /tmp/create_ap.wlan0.conf.P4mV3lTx/hostapd_ctrl
Configuration file: /tmp/create_ap.wlan0.conf.P4mV3lTx/hostapd.conf
Using interface wlan0 with hwaddr b0:f1:ec:7b:1a:2a and ssid "ckb"
wlan0: interface state UNINITIALIZED->ENABLED
wlan0: AP-ENABLED 
wlan0: INTERFACE-DISABLED 

the content of /etc/network/interfaces is :

# interfaces(5) file used by ifup(8) and ifdown(8)
# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d

auto wlan0
iface wlan0 inet dhcp

auto eth0
iface eth0 inet static
address  192.168.1.50
netmask 255.255.255.0
gateway 192.168.1.1
dns-nameservers 8.8.8.8 8.8.4.4