Could it be, that you NEED a Controller to be able to use the AnimBlueprint?
If you have no PlayerController, then you might want to use an AI Controller for that Pawn/Character.
This also happens if possessed by a custom player controller.
While debugging the ‘Get anim instance’ node return value pin shows the correct animation blueprint reference, but the return value of the cast node returns none. Is this specific to 4.11?