I came across this one while trying to add some sidebar content in my articles view. If the badge of an actor is being rendered through the (at)service call using ids, an error is thrown if the actor being called is somehow otherwise "active" on the view being rendered:
So, I'm actor #1 but not logged in and viewing an article that I did not author. Works fine. If I log in and view that same article, error is thrown. Separately, if I remain not logged-in but view an article that I authored the same error is thrown. Again, if not logged in but go back to another article that I did not author, everything works fine again.