stride3d/stride · error · ArgumentNullException

key

Error message

key

What it means

SetParam<T> throws ArgumentNullException("key") when the PermutationParameterKey<T> used to set a shader parameter is null. The key identifies which composition/permutation parameter receives the value. Fail-fast guard before writing into the parameter collection.

Solutions

1. Pass a valid PermutationParameterKey<T> (e.g. MyShaderKeys.TextureCount)
2. Confirm the key name matches a declared permutation key on the target shader
3. Guard against null keys resolved by name before calling SetParam

Example fix

// before
context.SetParam(ResolveKey("Color"), value); // ResolveKey may return null
// after
var key = ResolveKey("Color");
if (key != null) { context.SetParam(key, value); }

if (key is null) throw new InvalidOperationException("Permutation key not found");
context.SetParam(key, value);

static bool IsValidKey<T>(PermutationParameterKey<T> k) => k != null;

try { context.SetParam(key, value); }
catch (ArgumentNullException) { logger.LogWarning("Skipped SetParam for unknown key"); }

When it happens

Trigger: Calling ctx.SetParam<T>(null, value) — commonly when the key comes from a cache/lookup that returned null for an unknown parameter name.

Common situations: Renamed or removed permutation keys after shader refactors; dynamically resolved keys where the name doesn't match any declared key.

Related errors

• paramKey
• mixinTree
• compilerParameters
• registeredBuilders
• Invalid null mixin name

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/382ec39a7f6db743. Report an issue: GitHub.

Appendix: source

Thrown at sources/shaders/Stride.Shaders.Effects/ShaderMixinContext.cs:166

            }

            return null;
        }

        private PermutationParameterKey<T> GetComposeKey<T>(PermutationParameterKey<T> key)
        {
            if (compositionString == null)
            {
                return key;
            }
            key = key.ComposeWith(compositionString);
            return key;
        }

        public void SetParam<T>(PermutationParameterKey<T> key, T value)
        {
            if (key == null)
                throw new ArgumentNullException("key");

            var propertyContainer = parameterCollections.Count > 0 ? parameterCollections.Peek() : compilerParameters;
            Set(propertyContainer, key, value);
        }

        /// <summary>
        /// Removes the specified mixin from this instance.
        /// </summary>
        /// <param name="mixinTree">The mixin tree.</param>
        /// <param name="name">The name.</param>
        public void RemoveMixin(ShaderMixinSource mixinTree, string name)
        {
            var mixinParent = mixinTree;
            for (int i = mixinParent.Mixins.Count - 1; i >= 0; i--)
            {
                var mixin = mixinParent.Mixins[i];
                if (mixin.ClassName == name)
                {

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