OpenRA/OpenRA · error · YamlException

Weapons Ruleset does not contain an entry '{weaponToLower}'

Error message

Weapons Ruleset does not contain an entry '{weaponToLower}'

What it means

Thrown by ArmamentInfo.RulesetLoaded when the Armament's Weapon name (lowercased) is absent from the ruleset Weapons table. Every armament must resolve to a WeaponInfo at load time; a missing weapon aborts ruleset assembly with a YamlException.

Source

Thrown at OpenRA.Mods.Common/Traits/Armament.cs:96

		[CursorReference]
		[Desc("Cursor to display when hovering over a valid target.")]
		public readonly string Cursor = "attack";

		// TODO: same as above
		[CursorReference]
		[Desc("Cursor to display when hovering over a valid target that is outside of range.")]
		public readonly string OutsideRangeCursor = "attackoutsiderange";

		[Desc("Ammo the weapon consumes per shot.")]
		public readonly int AmmoUsage = 1;

		public override object Create(ActorInitializer init) { return new Armament(init.Self, this); }

		public override void RulesetLoaded(Ruleset rules, ActorInfo ai)
		{
			var weaponToLower = Weapon.ToLowerInvariant();
			if (!rules.Weapons.TryGetValue(weaponToLower, out var weaponInfo))
				throw new YamlException($"Weapons Ruleset does not contain an entry '{weaponToLower}'");

			WeaponInfo = weaponInfo;
			ModifiedRange = new WDist(Util.ApplyPercentageModifiers(
				WeaponInfo.Range.Length,
				ai.TraitInfos<IRangeModifierInfo>().Select(m => m.GetRangeModifierDefault())));

			if (WeaponInfo.Burst > 1 && WeaponInfo.BurstDelays.Length > 1 && (WeaponInfo.BurstDelays.Length != WeaponInfo.Burst - 1))
				throw new YamlException($"Weapon '{weaponToLower}' has an invalid number of BurstDelays, must be single entry or Burst - 1.");

			if (WeaponInfo.ReloadDelay <= 0)
				throw new YamlException($"Weapon '{weaponToLower}' ReloadDelay value must not be equal to or lower than 0");

			base.RulesetLoaded(rules, ai);
		}
	}

	public class Armament : PausableConditionalTrait<ArmamentInfo>, ITick
	{

View on GitHub (pinned to a520984d91)

Solutions

Confirm the Weapon value matches (case-insensitively) an existing weapons.yaml entry.
Add the missing weapon definition to weapons.yaml.
Correct typos/whitespace in the Weapon field.
If migrating mods, port the required weapon definitions alongside the actor.

Defensive patterns

Strategy: validation

Validate before calling

// Validate armament weapon exists at load time
var key = weapon.ToLowerInvariant();
if (!rules.Weapons.ContainsKey(key))
    throw new YamlException($"Armament weapon '{key}' not found in ruleset.");

Type guard

bool WeaponExists(Ruleset rules, string name) => rules.Weapons.ContainsKey(name.ToLowerInvariant());

Prevention

Ensure every Armament Weapon matches a weapons.yaml entry.
Run a ruleset validator that resolves all weapon references.
Port weapon definitions when migrating actors between mods.

When it happens

Trigger: An actor's Armament trait declares a Weapon that is not defined in weapons.yaml, or is defined in a mod not loaded. Raised during RulesetLoaded for the actor.

Common situations: Typo in the Weapon field; referencing a weapon removed in a mod update; case mismatch; weapon defined under a different mod/parent; copy-pasting an actor without copying its weapon.

Related errors

AI-assisted analysis of OpenRA/OpenRA@a520984d91 (2026-08-13). Data as JSON: /api/errors/276601d11331007a. Report an issue: GitHub.