OpenRA/OpenRA · error · InvalidDataException

Actor {id} of unknown type {reference.Type.ToLowerInvariant(

Error message

Actor {id} of unknown type {reference.Type.ToLowerInvariant()}

What it means

Thrown as an InvalidDataException by the EditorActorPreview constructor when the actor reference's Type (lowercased) is not present in world.Map.Rules.Actors. The editor loads a preview for each actor in a map; if the actor type string doesn't match any registered actor definition (case-insensitively via ToLowerInvariant), the lookup fails and the preview cannot be built.

Source

Thrown at OpenRA.Mods.Common/Traits/World/EditorActorPreview.cs:68

		SelectionBoxAnnotationRenderable selectionBox;
		IActorPreview[] previews;

		public EditorActorPreview(WorldRenderer worldRenderer, string id, ActorReference reference, PlayerReference owner)
		{
			ID = id;
			this.reference = reference;
			Owner = owner;
			this.worldRenderer = worldRenderer;

			if (!reference.Contains<FactionInit>())
				reference.Add(new FactionInit(owner.Faction));

			if (!reference.Contains<OwnerInit>())
				reference.Add(new OwnerInit(owner.Name));

			var world = worldRenderer.World;
			if (!world.Map.Rules.Actors.TryGetValue(reference.Type.ToLowerInvariant(), out Info))
				throw new InvalidDataException($"Actor {id} of unknown type {reference.Type.ToLowerInvariant()}");

			GenerateFootprint();
			UpdateFromCellChange();

			tooltip = Info.TraitInfos<EditorOnlyTooltipInfo>().FirstOrDefault(info => info.EnabledByDefault) as TooltipInfoBase
				?? Info.TraitInfos<TooltipInfo>().FirstOrDefault(info => info.EnabledByDefault);

			DescriptiveName = tooltip != null ? tooltip.Name : Info.Name;

			terrainRadarColorInfo = Info.TraitInfoOrDefault<RadarColorFromTerrainInfo>();
			UpdateRadarColor();
		}

		public EditorActorPreview WithId(string id)
		{
			return new EditorActorPreview(worldRenderer, id, reference.Clone(), Owner);
		}

View on GitHub (pinned to a520984d91)

Solutions

1. Correct the actor type name in the map's actor definitions to match a registered actor.
2. Restore or re-add the missing actor definition in the mod rules.
3. Ensure the correct mod providing that actor is loaded when opening the map.

Example fix

// before (actor renamed from 'e1' to 'gi' in new mod version)
Actor0:
	Type: e1
// after
Actor0:
	Type: gi

if (!world.Map.Rules.Actors.ContainsKey(reference.Type.ToLowerInvariant()))
    throw new KeyNotFoundException($"Actor type '{reference.Type}' is not defined in the loaded rules.");

static bool IsKnownActor(Map map, string typeName) =>
    map.Rules.Actors.ContainsKey(typeName.ToLowerInvariant());

When it happens

Trigger: A map's actor definitions reference an actor type that is not defined in the mod's rules (missing, renamed, or from an unloaded mod). reference.Type.ToLowerInvariant() is not a key in world.Map.Rules.Actors.

Common situations: Opening a map in the editor after a mod update renamed/removed an actor type; map referencing actors from a mod that is no longer loaded; typo in an actor type name in map YAML.

Related errors

• Actor {ID} must define Location or CenterPosition
• EditorActorLayer must not be defined on the world actor.
• No rules definition for unit {name}
• {debugName}, duplicate values found for the following keys:
• Actor type {name}: {e.Message}

AI-assisted analysis of OpenRA/OpenRA@a520984d91 (2026-08-13). Data as JSON: /api/errors/1873b15a98e75ccd. Report an issue: GitHub.