kubuntu 18.04 no wifi on network manager but in terminal is detected

WTFFFFF! NO WIFI ON KDE NETWORK MANAGER APPLET but with iwlist is detected  (07:00.0 Network controller: Qualcomm Atheros AR9485 Wireless Network Adapter (rev 01) so the driver was working properly infact i connect to a open wifi , without password. so WHY!!! i guess for a problem with some systemd conf files anyway….



 systemctl --type service

which has this silly answer :

systemd-networkd-wait-online.service loaded failed failed Wait for Network to be Configured

checking even the wpa_supplicant service with

systemctl status wpa_supplicant.service
Failed to initialize control interface '/run/wpa_supplicant'.
 You may have another wpa_supplicant process already running or the file was
 left by an unclean termination of wpa_supplicant in which case you will need
 to manually remove this file before starting wpa_supplicant again.
sudo systemctl status NetworkManager.service

i got even this shit

 error>   sup-iface[0x56547f32d5b0,wlp7s0]: error adding interface: wpa_supplicant couldn't grab this interface.

now how to fix it !?

sudo systemctl  stop NetworkManager.service
sudo systemctl  stop wpa_supplicant.service 
sudo systemctl  start wpa_supplicant.service 
sudo pkill wpa_supplicant 
sudo systemctl  start wpa_supplicant.service
sleep 4
sudo systemctl start NetworkManager.service


result 😀



  1. CHECK IF YOUR CARD IS ENABLE ON BIOS , if you want to see that just do  on therminal rfkill list  and make sure it’s all NO
  2. ENABLE YOUR CARD  sudo ifconfig XXXX up ( your card name that should be wlp7s0 you can get the name from ifconfig alone without optios) as you can see here

    sudo rfkill unblock all
    0 wlan phy0 unblocked unblocked
    1 bluetooth hci0 unblocked unblocked
    sem@semvaio18:~$ ifconfig
    lo: flags=73 mtu 65536
    inet netmask
    inet6 ::1 prefixlen 128 scopeid 0x10
    loop txqueuelen 1000 (Local Loopback)
    RX packets 31198 bytes 1590503 (1.5 MB)
    RX errors 0 dropped 0 overruns 0 frame 0
    TX packets 31198 bytes 1590503 (1.5 MB)
    TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
    wlp7s0: flags=4163 mtu 1500
    inet netmask broadcast
    inet6 fe80::1e7f:5239:d350:a751 prefixlen 64 scopeid 0x20 ether a4:19:32:c1:1c:23 txqueuelen 1000 (Ethernet)
    RX packets 4184 bytes 2798289 (2.7 MB)
    RX errors 0 dropped 0 overruns 0 frame 0
    TX packets 4560 bytes 1447049 (1.4 MB)
    TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

  3. try to see if wpa supplicant is installed : sudo apt-get install wpasupplicant
  4. if you can’t see the network applet on your panel well maybe the network manager service is not started so start it and enable it with : sudo systemctl enable NetworkManager.service ; sudo
    systemctl start NetworkManager.service
  5. check the systemd-networkd-wait-online.service with systemctl status systemd-networkd-wait-online.service actuyally it gives me error even when i am connect so i guess it’s not so important like i thought but he has given me a hint to fix this shit so ..
  6. another command useful to get errors it’s this
    journalctl -xe

from here https://forums.linuxmint.com/viewtopic.php?t=171819
this is for my own use interfaces

auto wlp7s0
iface wlp7s0 inet dhcp
wireless-power off

sudo kate /etc/default/crda


Share Files with a simple Ethernet cable and kde or terminal via SSH.


sudo apt-get install openssh-client openssh-server




In this scheme we have 2 computers connect to internet via wifi , thought a router and they are DIRECTLY connect via ethernet CABLE. Ok you can use wifi and ssh to connect but to copy and paste file a direct ethernet cable it’s faster  than samba or  even other ways 
A very crucial point it’s the IP ADRRES WE ARE GOING TO USE FOR ETHERNET CONNETION THE ROUTER INFACT HAS THIS IP ADDRESS so we need to connect the ethernet cards to ANOTHER NET infact the address it’s

192.168 .0. 70\71

To undestand how to achieve that for your network then run this command


as you can see i have


enp9s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
inet  netmask
inet6 ::1  prefixlen 128  scopeid 0x10
loop  txqueuelen 1  (Local Loopback)
RX packets 724210  bytes 36282573 (36.2 MB)
RX errors 0  dropped 0  overruns 0  frame 0
TX packets 724210  bytes 36282573 (36.2 MB)
TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlp7s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
inet  netmask  broadcast
inet6 fe80::274c:b2d2:57ed:5074  prefixlen 64  scopeid 0x20 ether a4:17:31:c9:1c:29  txqueuelen 1000  (Ethernet)
RX packets 102070  bytes 133111059 (133.1 MB)
RX errors 0  dropped 0  overruns 0  frame 0
TX packets 55750  bytes 7139648 (7.1 MB)
TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

so i am connected with wifi , wlp7s0 , and i have a ethernet pci card called enp9s0 .

To get the configuration of fig 1  you can configure the network with a terminal or with networkmanager ( run on terminal)


If you prefer to use a terminal to connect  you have to do :

sudo ifconfig enp9s0 up

on the other computer instead you have to do

sudo ifconfig enp3s6 up


As usual it will ask for password and you get in

ssh  charlotte@

he authenticity of host ‘ (’ can’t be established.
ECDSA key fingerprint is SHA256:iHDff80m3z27FyvloThybOLBbvZcEjyVsm5U9Za1BS8.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added ‘’ (ECDSA) to the list of known hosts.

charlotte@’s password:

Welcome to Ubuntu Zesty Zapus (development branch) (GNU/Linux 4.9.0-11-generic x86_64)


So now you can copy and paste files or edit with vi , with the code

scp filefromcomputer2.txt  sem@



Other way could be instead the network manager gui


An  on ipv4 add address in the first computer and in the second we have to replace that ip with subnet mask it’s alwasy for every computer

After that yuu have to click on connect in the normal way on network manager applet\plasmoid.

to share copy edit file you can use dolphin as you can see here :

STEP 1dolphin-nexus0



And dolphin will automatically open ,if you did all right , after you write down the password.

networking restart kubuntu doesn’t work

sudo ifdown --exclude=lo -a && sudo ifup --exclude=lo -a