Ubuntu – network-manager not working in ubuntu 14.04

Please try:

sudo apt-get install  linux-backports-modules-cw-3.8-precise-generic

I believe cw-3.8 includes the modalias for your device.

If your device is still not shown, please post:

modinfo ath9k | grep 0036
dmesg | grep ath

Please get a working ethernet connection, open a terminal and do:

sudo apt-get install linux-headers-generic build-essential

Download this file to your desktop: https://www.kernel.org/pub/linux/kernel/projects/backports/2013/11/13/backports-20131113.tar.bz2 Right-click it and select 'Extract Here.' Back to the terminal:

cd Desktop/backports-20131113/
make defconfig-ath9k
make
sudo make install

Reboot and let us know if it is working. You will have compiled the driver for your currently running kernel only. When Update Manager installs a newer kernel version, also known as linux-image, after you reboot, re-compile:

cd Desktop/backports-20131113/
make clean
make defconfig-ath9k
make
sudo make install
sudo modprobe ath9k

Please retain the files and these instructions for that time.

A bug with Network Manager obviously can be solved this way:

First you need anyway purge hostapd together with configuration:

sudo apt-get purge hostapd

Then try to reinstall network-manager, and this way your configuration of network-manager will be saved:

sudo apt-get install --reinstall -fmu network-manager

_{where -f is fix-broken, -m is fix-missing and -u is show upgraded}

sudo reboot

OR completely purge hostapd & network-manager together with their configurations and again freshly install network-manager by single command:

sudo apt-get purge -y hostapd && sudo apt-get purge -y network-manager && sudo apt-get install network-manager && sudo reboot

For a chance to have hostapd installed my opinion you need to go step-by-step this guide:
WifiDocs / MasterMode

Then, if success you can begin stepping second guide to setup your wifi from there:
Using hostapd on Ubuntu to create a wifi access point

Cited the part 5.Troubleshooting from second guide:

If you have network-manager configured to use your wifi card, you should disable auto-connect for all the wireless connections. Otherwise, it may interfere with hostapd. If some frequencies are disabled, make sure your driver is set to use the right regulatory domain. You can see the current one with:

iw reg get

If it says country 00, you need to set it manually, in /etc/default/crda. To set it manually you need (at least for some cards) to have cfg80211 and mac80211 installed as kernel modules. You can check if they’re installed as modules by using:

zcat /proc/config.gz

Look for CONFIG_CFG80211=m, if it says “=y” then it’s compiled into the kernel, and you’ll need to re-install your kernel. If you’re using an Atheros card, you may also need to set the region in the driver. Do this by adding “cfg80211 ieee80211_regdom=US” to /etc/modules

Last sentence is about your country code sure.