nopCommerce - Missing configure button in plugin

Scenario

I am building a new nopCommerce plugin that will handle the CyberSource Order Status Notification. Everything went smoothly and got all my code compiled. After the installation of the plugins, I found there is a missing configure button that would normally be there.

Solution

I revisited the source code of my other plugins, it compiles fine and didn't spot any obvious error. I went over to some of my notes and wiki then I found I missed a very little step.

public class CyberSourceOSNPlugin : BasePlugin, IMiscPlugin

I created the plugin class file but left out the bit where I have to implement an interface of IPlugin. After I implemented the interface, it is working fine again.