Question: I have installed ubuntu 14.04 and it seems like I cannot actually create a VPN connectionor manage the network devices.

When I am accessing the network connection using the network icon at the gnome bar I enter the "Edit Connections" -> Add -> PPTP -> Create -> I cannot edit any property of the window.  

It states "Editing VPN connection 1" in the top of the windows\form but I cannot edit anything and there for cannot create the VPN connection.

I have also tried to use the "System Settings"-> Network -> "+" button -> interface VPN -> Create -> PPTP -> create -> and again cannot touch any property of the windows.

Maybe it's related to permissions but I don't see any place I can run the "System Settings"-> Network or any other related thing that allows me to elevate my permissions from just "user mode" to a "privileged mode" while I still can run sudo using my password.

Answer: 
I had encountered the same problem - dialog was disabled.

**The solution that worked for me was:**

1. Installing network-manager-gnome: `sudo apt-get install network-manager-gnome`
2. Starting network-manager: `sudo start network-manager` (In case it is already running might need to stop it and then start again)

After that I tried to create new vpn connection as described and the dialog was enabled.
If the VPN configuration tab is greyed out it's because the required plugins are not installed for Gnome NetworkManager. The following plugin should be installed:

**network-manager-pptp** and **network-manager-pptp-gnome** - network management framework PPTP plugin GNOME GUI

To install the above plugin use the apt-get command as follows:

```
$sudo apt-get install network-manager-pptp

```

Now, you can add vpn connection to your system using NetworkManager itself. You may need to restart the NetworkManager as follows:

```
# /etc/init.d/network-manager restart

```

Hope it could help.