Do not use ContentTypeId when creating CustomActions
I was preparing hands-on-lab to equip some of the developers with the skillsets to deliver a project. When trying to create a CustomAction, the SDK said that ContentTypeId is used to specify the ID of a content type to associate with the custom action. However, that doesn't work.
Instead, use RegistrationId to specify the ID of the content type you would like to associate, and assign "ContentType" to RegistrationType does what I need easily...
Now, any tips for a newbie running a hands-on-lab?