With default settings, the NetworkManager applet on openSUSE is disabled. Here’s how to enable it.
When I installed openSUSE 42.2 and Xfce, I had a NetworkManager applet but it was disabled. There was an X in the bottom right corner of the icon, and while clicking on it opened a configuration menu, the menu was entirely gray, suggesting there was a permission problem or it was disabled.
It’s the latter. To enable it, open YaST. In the System section, open the Network Settings tool. In the Global Options tab under “General Network Settings”, find the Network Setup Method drop-down. On my box, the default setting was Wicked Service. I changed it to NetworkManager Service, pressed OK to enable the new setting, and with that the NetworkManager applet came to life.
Doing so disables parts of the Network Settings tool in YaST, so henceforth you’ll use the NetworkManager applet to administer some of your network settings.
This information refers to openSUSE 42.2 and was last updated 11 February 2017.