Wrong class plugged into a pin expecting a specific type

Why: A pin expected an actor of type '{expected}' (or subclass) but you connected a '{actor}' which doesn't inherit from it. Fix: Either: (a) change your '{actor}' to inherit from '{expected}' by reparenting it (File → Reparent Blueprint), or (b) use a Cast To node to verify the type at runtime, or (c) plug in a different actor that IS a subclass of '{expected}'.

Event Dispatcher binding has wrong parameter types

Why: You're binding a function to an Event Dispatcher (Delegate), but the function's parameters don't match the dispatcher's expected signature '{expected}'. You passed '{got}'. Fix: Either: (a) change your function's input parameter types to match the dispatcher (open the function → My Blueprint → Inputs section → match types one-by-one), or (b) bind a DIFFERENT function whose signature already matches. The Details panel of the Bind Event node shows the expected signature.

Not_PreBool — logical NOT

NOT Boolean — logical NOT (invert boolean)

BooleanAND — logical AND

OR=BooleanOR, NOT=Not_PreBool, XOR=BooleanXOR

OR Boolean — logical OR of two booleans

IsInAir (IsFalling) — true if character is in the air

Call on the CharacterMovementComponent, not directly on Character. Or use IsMovingOnGround.

Less (float) — A < B

WasInputKeyJustPressed — true only on the frame the key was pressed

RandomBool — return random true or false