I'm working on an embedded device running Ubuntu 14.04.
When I first logged in I had no problem using nmcli dev wifi and it would return 3 results. (Though the wifi card must be weak as my laptop returns over 20 results.)
I then used:
nmcli nm wifi off
rfkill unlock wlan
Followed by running a wifi AP with hostapd, which was successful.
I then turned AP off and ran nmcli nm wifi on and restarted the device.
After restarting the nmcli dev wifi command "works" (no errors) but returns no networks.
Does anyone have any ideas of steps I can take to get more information on the state of the network interface or wifi card?