Kubuntu Hidden Wireless Network

Problem
There seems to be general issue with KDE's Network Manager and hidden wireless networks. [You can see (and vote for!) the bug here: https://bugs.kde.org/show_bug.cgi?id=209464.] You are trying to connect to a hidden network, and you create a profile for the specific wireless network in the KDE Network Manager. But for some reason you still can't connect.

I have encountered this problem for a while (Kubuntu 9.10, 10.04, 10.10, 11.04, 11.10, 12.04, and 12.10], but I finally found a solution today. A quick look tells me this bug has been around existed at least for 2 years. Pity they haven't fixed it.

Solution
Quick solution is to run this from command line:

sudo iwconfig wlan0 essid name_of_the_hidden_essid

This works even better if you have used KDE Network Manager to create a wireless profile with this hidden network's name already. You can setup password and such. This command only invokes connection to it, which is the real bug in the manager. It will read the profile you have previously stored.

Other solutions are to use a different network Manager, such as the network manager from Gnome/Ubuntu.

An even easier solution would be to just start broadcasting the SSID.

Network Management Disabled

I am surprised I have not mentioned this before. This is a recurrent bug that's been cropping up in KDE 4 since version 4.3 as far as I can tell. (It may have started later, so don't quote me on the exact date, and it might have nothing to do with KDE itself, and might be an Ubuntu thing.)

The symptoms are the computer boots, the desktop environment loads (Gnome, KDE, etc.) and there is no Internet, when there should be. You click on the Network Manager and it tells you "Network Management Disabled." Bug report here. This bug has come and gone for me for a while now.

The problem is an incorrectly configured configuration file. (Basically, this is a bug that should never have happened but it did. Thankfully it's easy to fix.)

Open this file /var/lib/NetworkManager/NetworkManager.state with Admin privileges, and make the following changes. (If you need help on editing a system text file / configuration file, see this Article for a simple New Users guide.)

NetworkingEnabled=false

to

NetworkingEnabled=true

Save the file and close it. There may be a system service you can restart, but I cannot recall it at this time. Just reboot and your network should return to normally.