Connection problems can occur. Some common problems related to NetworkManager include the applet not starting, a missing VPN option, and issues with SCPM. Methods for resolving and preventing these problems depend on the tool used.
NetworkManager applet should start automatically if the network is set up for NetworkManager control. If the applet does not start, first make sure that the appropriate package for your desktop environment is installed. If you are using KDE, the package is NetworkManager-kde. For GNOME the package is NetworkManager-gnome.
If the desktop applet is installed but is not running for some reason (perhaps you quit it accidentally), start it manually with the command knetworkmanager (KDE) or nm-applet (GNOME).
Support for NetworkManager, applets, and VPN for NetworkManager is distributed in separate packages. If your NetworkManager applet does not include the VPN option, check if the packages with NetworkManager support for your VPN technology are installed. For more information, see Section 10.3, NetworkManager and VPN. />.
You are probably using SCPM together with NetworkManager. NetworkManager is not currently able to work with SCPM profiles. Do not use NetworkManager together with SCPM when SCPM profiles also change network settings. To use SCPM and NetworkManager at the same time, disable the network resource in SCPM configuration.
If you have configured your network connection correctly and all other components for the network connection (router, etc.) are also up and running, it sometimes helps to restart the network interfaces on your computer. To do so, log in to a command line as root and run rcnetwork restart.