If I create a Start Dialogue Tree Node in an FSM, I am unable to pick a Dialogue Actor or subclass. The selection dialog is empty and I cannot drag and drop scene items into the field.
I must change the generic type in StartDialogueTree.cs, ln 12, from IDialogueActor to DialogueActor. I can then use both DialogueActors and their subclasses.
This is a know issue, but it is more of a Unity ObjectField issue to be honest.
If you drag & drop the Dialogue Actor component itself, then you will be able to assign it to the field. However, dragging a gameobject that has a Dialogue Actor component attached, will not allow you to make the assignment as it should.
Thus, if you want to keep the original code to be of type IDialogueActor, please remember that assignment is possible by drag and drop the Dialogue Actor component itself.