All, I'm making my way through the Learning Path. On module 4.9.2 I *think* I have restricted the association correctly (my data view looks like the screen shot at the bottom of 4.9.2). However, in the next module, it says "Remember to use the TrainingEvent constraint on the Add button!" I can't see how to do that, and as a result I have an error telling me "An object of type Registration should be passed to the page, but no object is available." The page that it's linking to has a data view of Registration and also looks like the associated module screen shot, so I cannot see what I am doing wrong. Any ideas, please? Thanks in advance.
I think these are the settings that you need for your new button. The entity setting defines what type of object you are creating.
I think the constraint is referring to you selecting the association between the object on your page and the object you are creating. I think in this case you are talking about Training event and registration?
Edit: This was the web modeler. Here is a screenshot for the desktop modeler.