What causes "clips" in Unity-Technologies/UnityCsReference?

Initialize the clips array before passing it, or check for null before calling AddElements.

Unity-Technologies/UnityCsReference · error · ArgumentNullException

clips

Error message

clips

What it means

ArgumentNullException thrown by AudioRandomContainerExtensions.AddElements(AudioClip[] clips) when the clips array is null. This is a standard null-argument guard ensuring the clips parameter is a valid array before accessing its Length property.

Source

Thrown at Editor/Mono/Audio/AudioRandomContainerExtensions.cs:40

        ValidateContainer(container);

        if (count <= 0)
            throw new ArgumentOutOfRangeException(nameof(count), "Must be greater than zero.");

        AddElementsInner(container, count, (i, element) => { });
    }

    /// <summary>
    /// Adds a given number of new <see cref="AudioContainerElement"/> objects with clips assigned to <see cref="AudioRandomContainer.elements"/>.
    /// </summary>
    /// <param name="container">The instance to add the elements to.</param>
    /// <param name="clips">An array of <see cref="AudioClip"/> objects to be assigned to each new element.</param>
    internal static void AddElements(this AudioRandomContainer container, AudioClip[] clips)
    {
        ValidateContainer(container);

        if (clips == null)
            throw new ArgumentNullException(nameof(clips));

        if (clips.Length == 0)
            throw new ArgumentException("Must not be empty.", nameof(clips));

        AddElementsInner(container, clips.Length, (i, element) =>
        {
            if (clips[i] != null)
                element.audioClip = clips[i];
        });
    }

    static void ValidateContainer(AudioRandomContainer container)
    {
        if (container == null)
            throw new ArgumentNullException(nameof(container));

        if (!EditorUtility.IsPersistent(container))
            throw new ArgumentException("Must be a persistent asset.", nameof(container));

View on GitHub (pinned to 225b0fbdb5)

Solutions

Initialize the clips array before passing it, or check for null before calling AddElements.
If clips may legitimately be absent, guard the call: if (clips != null) container.AddElements(clips);
Ensure SerializedProperty.arraySize > 0 before extracting AudioClip elements into an array.
Use Array.Empty<AudioClip>() as a default instead of null, then let the empty-check guide behavior.

Example fix

// before
container.AddElements(myClips); // myClips may be null
// after
if (myClips != null && myClips.Length > 0)
    container.AddElements(myClips);

Defensive patterns

Strategy: type-guard

Validate before calling

// Null-check clips before calling AddElements
if (clips != null)
    container.AddElements(clips);

Type guard

static bool IsValidClipsArray(AudioClip[] clips) => clips != null && clips.Length > 0;

Prevention

Initialize AudioClip arrays with Array.Empty<AudioClip>() rather than leaving them null.
Null-check arrays read from SerializedProperty before use.
Assign default-empty arrays in field initializers to avoid null propagation.
Validate array references from deserialized or network data before passing to editor APIs.

When it happens

Trigger: Calling container.AddElements(null) or passing a variable that was never assigned. Occurs when a clips array field is uninitialized, a serialized property resolves to null, or a code path skips array initialization before calling AddElements.

Common situations: Editor scripts that read an AudioClip[] from a SerializedProperty that is unassigned, drag-and-drop handlers where no clips were dropped, deserialized data with missing clip arrays, conditional code paths that leave the array null.

Related errors

AI-assisted analysis of Unity-Technologies/UnityCsReference@225b0fbdb5 (2026-08-13). Data as JSON: /api/errors/1b8b25cf132bfddc. Report an issue: GitHub.