Parent Class

The base class your Blueprint inherits from (e.g. Actor, Pawn, UserWidget). Determines available functions and components.

Function name collision with parent class or duplicate

Why: You created a function named '{fn}' that conflicts with one already defined — either by the parent class (which you should Override instead) or another function in this same Blueprint. Fix: If you meant to override a parent function: delete your function, then right-click in My Blueprint → Override Function → pick '{fn}' from the list. If you meant a separate function: rename yours to something unique (e.g. '{fn}_Custom').

UserWidget

Parent class for Widget Blueprints. Override Construct, Tick, OnPaint, etc.

Overriding a function but didn't call the parent version

Why: When you override a parent function (like BeginPlay or Tick), the parent's logic usually still needs to run. Forgetting to call Parent: <FunctionName> can break initialization. Fix: In your overridden function, right-click in empty space → search for 'Parent: <FunctionName>' (e.g. Parent: BeginPlay). Add that node. Wire it to the exec input early in your function, before your custom logic.

SetRelativeRotation on component — set component rotation relative to parent

SetRelativeLocation on component — set component position relative to parent

K2_SetRelativeLocation. USceneComponent method.

GetAllActorsOfClass — find all actors of a specific class in the level

UGameplayStatics::GetAllActorsOfClass. Expensive — cache results, don't call every tick.

GetActorOfClass — find first actor of a class in the world

Pure node. Returns null if none found. Cheaper than GetAllActorsOfClass for single-actor searches.

GetActorOfClass — find first actor of class in level

UGameplayStatics::GetActorOfClass. Returns first found. Cheaper than GetAllActorsOfClass.

CreateWidget — create widget instance from class

K2Node_CreateWidget. Class is the Widget Blueprint class reference.