Question: I want to configure a VPN connection, so choose VPN Connections->Configure VPN..., and I get to the Network Connections dialog. But the Add button is disabled. How do I enable it?

![enter image description here](https://i.stack.imgur.com/9QT1s.png)

Answer: 
This sounds like your issue. I found it in this articled titled: [Gnome Network Manager VPN Tab Disabled ( Greyed out )](http://www.cyberciti.biz/faq/deiban-ubuntu-linux-networkmanager-pptp-cisco-vpn-tab-disabled/).

                   ![ss #1](https://i.stack.imgur.com/BmozQ.png)

*excerpt from the article*

> 
> The Add tab is greyed out when required plugins are not installed for Gnome NetworkManager. The following plugins should be installed under Debian / Ubuntu Linux:
> 
> 
> 1. **network-manager-openvpn** and **network-manager-openvpn-gnome** - network management framework OpenVPN plugin GNOME GUI
> 2. **network-manager-pptp** and **network-manager-pptp-gnome** - network management framework PPTP plugin GNOME GUI
> 3. **network-manager-strongswan** - network management framework strongSwan ipsec vpn plugin
> 4. **network-manager-vpnc** and **network-manager-vpnc-gnome** - network management framework (VPNC plugin GNOME GUI)
> 
> 
> To install all of the above plugins use the apt-get command as follows:
> 
> 
> 
> ```
>   $ sudo apt-get install network-manager-openvpn network-manager-pptp \
>         network-manager-pptp-gnome network-manager-vpnc
> 
> ```
> 
> The following plugins should be installed under RHEL / Fedora / CentOS / Scientific Linux / Red Hat Enterprise Linux desktop systems:
> 
> 
> 1. **NetworkManager-openvpn** : NetworkManager VPN plugin for OpenVPN
> 2. **NetworkManager-pptp** : NetworkManager VPN plugin for pptp
> 3. **NetworkManager-vpnc** : NetworkManager VPN plugin for vpnc
> 
> 
> To install all of the above plugins use the yum command as follows:
> 
> 
> 
> ```
>   $ sudo yum install NetworkManager-vpnc NetworkManager-pptp \
>         NetworkManager-openvpn
> 
> ```
> 
> Now, you can add vpn connection to your system using NetworkManager itself. You may need to restart the NetworkManager as follows:
> 
> 
> 
> ```
>   $ sudo NetworkManager restart
> 
> ```
> 
> 

                   ![ss #2](https://i.stack.imgur.com/5kT8Q.png)
You have to install the network manager:

```
sudo aptitude install network-manager-vpnc

```

As well as the gnome client:

```
sudo aptitude install network-manager-vpnc-gnome

```