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Originally posted by: rboccuzziThis isn't a bug, but expected/planned behavior. The reason being, those input pins are actually inherited from the base node. The base node pins are always first, and always there, which allows us to resolve updates to a base node when pins are added or deleted in a sensible way when someone also adds pins to the inherited or instantiated (placed) node. This gives consistent and expected behavior to nodes based on the node type they come from.
Ideally, I woudl agree that the UI would give a little better feedback to let you know WHY you can't do what you are trying, however.
Cheers
Rich