Network Manager doesn't show Wireless connection

Question

I've just installed on my Debian Sid with XFCE4 network manager, but I have a problem, no wireless connection are shown. What Should I do? I used to use wicd but I had problems to connect to free wifi :S I don' t know why.

However now I'm connected from terminal, but I don't know why connections aren't shown in network manager..

Sameone can help me? Thank you.

EDIT: Now is showing but network manager gives me this error:

EDIT2:

My /etc/network/interfaces

auto lo
iface lo inet loopback

Answer 1

1. You can use the Network-Manager or wicd, but not the 2 at same time

   apt-get remove wicd
   

2. Find the network device

   lspci -nn | grep -i network
   

3. Verify the kernel module

   lspci -k | grep -i network -A 2
   

   The ouput should be somthing like

    02:00.0 Network controller: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller (rev 01)
         Subsystem: AzureWave Device 2047
         Kernel driver in use: bcma-pci-bridge
   

4. If not, try to install bcma from synaptic or Software Center

   apt-get update && apt-get install wpasupplicant wireless-tools 
   ifconfig wlan0 down
   ifconfig wlan0 up
   

Answer 2

If possible, download and install wireless-tools . Once installed and you know for a fact that there is at least one wi-fi AP in the vicinity which is up and running then do :-

$ sudo iwlist wlan0 scan

Let us know what is the output of that. Do you get something like :-

lan0     Scan completed :
          Cell 01 - Address: xx:xx:xx:xx:xx:xx
                    Channel:8
                    Frequency:2.447 GHz (Channel 8)
                    Quality=33/70  Signal level=-77 dBm  
                    Encryption key:on
                    ESSID:"dlink"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              9 Mb/s; 12 Mb/s; 18 Mb/s
                    Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
                    Mode:Master

As can be seen you get the ESSID of the AP as well as what rates it can work at. Would at least get you something more than now.

Answer 3

The connection's file may be inaccessible by NetworkManager. According to this page, you must change mode of the file.

sudo chmod 600 /etc/NetworkManager/system-connections/[connection 1]

and then restart the Networking service:

servive NetworkManager stop
servive NetworkManager start
sudo ifconfig eth0 down
sudo ifconfig eth0 up
sudo /etc/init.d/networking restart

or the other commands for restarting networking.

Answer 4

Yesterday, I upgraded from Ubuntu 16.10 to Ubuntu 17.04 and my wifi stopped working.

I noticed that I could still set up wifi manually in the console but the network manager applet wouldn't show any wifi spots and also not the active connection.

After spending 3 hours on the problem, I could fix it by a very simpel step, namely modifying /etc/network/interfaces by removing (or commenting out using #) the following two lines:

auto wlan0
iface wlan0 inet dhcp

I hope this might be useful for others!