What do you see? Is it just empty? Be sure the class name listed for "Object Type" (at the top left of my screen shot) matches the "Class Name" at the bottom and both are SAE-HRServices-Data-HRPlan. If that is all correct please check the definition of the SAE-HRServices-Data-HRPlan to be sure the key is set there, this should have been done by the wizard but lets check anyway (see my second screen shot).
Ok I think I got it - when I manually entered the class name , cut and paste from the object type there was no option to enter the parameter. However, when I selected it using the smart prompt it appeared.