Before version 7.5.2.1, when working on a sub-statechart, the user interface allowed you to open the Features window for the parent state and enter code in the Action on entry, Action on exit, and Reactions In State fields even though the code would not be generated. Now, these fields are read-only. If you want to define actions for the parent state, you must do so on the parent statechart.
If an existing model contains actions defined for parent states on sub-statecharts, this information will be lost if you open the model in version 7.5.2.1 and save it.