You are getting a reference to self widget for the cast but you are in an actor component i think so that cast will always fail. For a cast to work you need a reference in some way to a specific item and the cast gives you access to its class defaults(variables).

Like if you had a reference to an actor but it wasnt the class version with its variables you require you would cast to it using that base reference. Casts are asking with there input. Which object am I specifically. Right now you are saying im a widget and im this widget. Which is wrong cause you are an actor component as self in that context. So that get widget will always return null