Problem: My actor doesn't seem to have a relationship with any other object! What happened?
Almost certainly the actor has been resized--stretched, skewed, or made proportionately larger or smaller. This wipes out all relationships between that actor and other objects because relationships are established by measuring the relative angles between the bones of each actor. Any change (like resizing) to an object that alters the angles of its bones automatically makes an existing relationship with that each meaningless and therefore void.
For example, consider an actor sitting in a chair. Notice how the enlarged actor must stretch his legs out, thereby changing the angles at his knees and ankles?
However, you can use a relationship for a standard size actor as a starting point for a relationship for a scaled actor. Start with a standard-size actor in the desired relationship, and select the actor. Also select your bigger or smaller actor. Then go to the Objects menu and select Swap Objects Positions. That will put the scaled object in the same position and same pose. You can then adjust the pose as needed, and if desired, store a new relationship.