BabylonJS/Babylon.js · error

When using ArrayBufferView to load data the file extension m

Error message

When using ArrayBufferView to load data the file extension must be provided.

What it means

When raw binary data (ArrayBufferView) is passed to SceneLoader.LoadDataAsync / ImportMeshAsync-style entry points, SceneLoader cannot infer which loader plugin to use because there is no filename or URL to inspect. The caller must supply an explicit pluginExtension (e.g. "glb", "obj") so the right plugin can be selected.

Source

Thrown at packages/dev/core/src/Loading/sceneLoader.ts:677

            onProgress(event);
        } catch (error) {
            Logger.Warn("Error in onProgress callback: " + getErrorMessage(error));
        }
    };
}

async function loadDataAsync(
    fileInfo: IFileInfo,
    scene: Scene,
    onProgress: ((event: ISceneLoaderProgressEvent) => void) | undefined,
    pluginExtension: Nullable<string>,
    name: string,
    pluginOptions: PluginOptions
): Promise<LoadedPluginData> {
    const directLoad = getDirectLoad(fileInfo.url);

    if (fileInfo.rawData && !pluginExtension) {
        throw new Error("When using ArrayBufferView to load data the file extension must be provided.");
    }

    const fileExtension = !directLoad && !pluginExtension ? getFilenameExtension(fileInfo.url) : "";

    let registeredPlugin = pluginExtension
        ? getPluginForExtension(pluginExtension, true)
        : directLoad
          ? getPluginForDirectLoad(fileInfo.url)
          : getPluginForExtension(fileExtension, false);

    if (!registeredPlugin && fileExtension) {
        if (fileInfo.url && !fileInfo.url.startsWith("blob:")) {
            // Fetching head content to get the mime type
            const response = await _FetchAsync(fileInfo.url, { method: "HEAD", responseHeaders: ["Content-Type"] });
            const mimeType = response.headerValues ? response.headerValues["Content-Type"] : "";
            if (mimeType) {
                registeredPlugin = getPluginForMimeType(mimeType);
            }

View on GitHub (pinned to 0592b347b8)

Solutions

1. Pass the pluginExtension parameter (e.g. "gltf", "glb", "obj") matching the data format.
2. Convert the raw data to a Blob/File with a proper filename and load that instead.
3. If the data is base64, embed it in a data: URL so the extension can be derived.

Example fix

// before
await BABYLON.SceneLoader.LoadDataAsync("", arrayBuffer, scene, null, "", ""); // throws

// after
await BABYLON.SceneLoader.LoadDataAsync("", arrayBuffer, scene, null, "glb", "");

function assertLoadArgs(data: unknown, pluginExtension?: string | null): void {
  if (data instanceof ArrayBuffer || ArrayBuffer.isView(data)) {
    if (!pluginExtension) throw new Error("pluginExtension is required when loading raw binary data");
  }
}

function isRawData(d: unknown): d is ArrayBufferView {
  return d !== null && typeof d === "object" && (ArrayBuffer.isView(d) || d instanceof ArrayBuffer);
}

try {
  await BABYLON.SceneLoader.LoadDataAsync("", buffer, scene, null, "glb", "");
} catch (e) {
  if ((e as Error).message.includes("ArrayBufferView")) {
    console.error("Supply a pluginExtension (e.g. 'glb') when passing raw buffers", e);
  }
}

When it happens

Trigger: Calling SceneLoader.LoadDataAsync (or ImportMeshAsync with file data) passing an ArrayBufferView as data and omitting the pluginExtension parameter.

Common situations: Loading scenes fetched manually via fetch()/XHR into ArrayBuffers; loading from IndexedDB or custom caches; migrating from URL-based loading to in-memory binary loading without updating the call signature.

Related errors

• Loading from ArrayBufferView can not be used with plugins th
• No scene available to import mesh to
• Cannot load file: a valid scene filename or root url was not
• No scene available to append to
• No plugin or fallback for ${pluginExtension ?? fileInfo.url}

AI-assisted analysis of BabylonJS/Babylon.js@0592b347b8 (2026-08-30). Data as JSON: /api/errors/e8562ab765def40a. Report an issue: GitHub.