BabylonJS/Babylon.js · error

Freezing active meshes was cancelled

Error message

Freezing active meshes was cancelled

What it means

Scene.freezeActiveMeshes() asks every object renderer to freeze its active meshes; this happens asynchronously via a retry helper (_RetryWithInterval). If any object renderer's freeze step reports failure (ok === false) or is cancelled (notCancelled === false, e.g. due to an error in a renderer), the scene throws this Error to abort the freeze operation instead of leaving the scene half-frozen.

Source

Thrown at packages/dev/core/src/scene.pure.ts:4645

            for (const task of objectRendererTasks) {
                task.objectRenderer._freezeActiveMeshes(freezeMeshes);
            }

            // Wait for all object renderers to finish freezing
            this._freezeActiveMeshesCancel = _RetryWithInterval(
                () => {
                    let ok = true;
                    let notCancelled = true;
                    for (const task of objectRendererTasks) {
                        ok &&= task.objectRenderer._isFrozen;
                        notCancelled &&= task.objectRenderer._freezeActiveMeshesCancel !== null;
                    }
                    if (ok) {
                        return true;
                    } else if (!notCancelled) {
                        // At least one object renderer cancelled freezing meshes because of an error
                        // Throws an error that will be caught by _RetryWithInterval.onError
                        throw new Error("Freezing active meshes was cancelled");
                    }
                    return false;
                },
                () => {
                    // All meshes of all object renderers could be frozen correctly
                    this._freezeActiveMeshesCancel = null;
                    this._activeMeshesFrozen = true;
                    this._activeMeshesFrozenButKeepClipping = keepFrustumCulling;
                    this._skipEvaluateActiveMeshesCompletely = skipEvaluateActiveMeshes;

                    onSuccess?.();
                },
                (err, isTimeout) => {
                    // An error occurred => not all meshes could be frozen
                    // Unfreezes all meshes so that we remain in a valid state
                    this._freezeActiveMeshesCancel = null;
                    this.unfreezeActiveMeshes();
                    if (!isTimeout) {

View on GitHub (pinned to 0592b347b8)

Solutions

1. Inspect the object renderers' _freezeActiveMeshes results/logs to find which renderer cancelled and fix the underlying error it hit
2. Retry freezeActiveMeshes after the scene and all renderers are fully ready (e.g. after assets finish loading / onReadyObservable fires)
3. Avoid mixing custom object renderers with mesh freezing, or ensure their freeze implementation returns true
4. If freezing is unstable, remove the freeze call and let the scene evaluate meshes each frame

Example fix

// before
scene.registerBeforeRender(() => { scene.freezeActiveMeshes(); });
// after
scene.executeWhenReady(() => { try { scene.freezeActiveMeshes(); } catch (e) { console.warn('freeze cancelled', e); } });

// Ensure scene is ready and no problematic object renderers are attached
if (scene.isReady() && scene.progressBar === undefined) {
  scene.executeWhenReady(() => scene.freezeActiveMeshes());
}

try {
  scene.freezeActiveMeshes();
} catch (e) {
  if (e instanceof Error && e.message === 'Freezing active meshes was cancelled') {
    // fall back to per-frame mesh evaluation; investigate renderer errors
    scene.unfreezeActiveMeshes?.();
  } else { throw e; }
}

When it happens

Trigger: Calling scene.freezeActiveMeshes() (or freezeActiveMeshes(update) in a render loop) when at least one attached object renderer errors or cancels during its _freezeActiveMeshes step; the retry/onError path surfaces the cancellation as this thrown error.

Common situations: Performance-tuning a Babylon.js scene by freezing meshes to skip mesh evaluation; custom object renderers or plugins whose freeze callback fails; scenes with renderers attached that are not ready when freeze is attempted.

Related errors

• Geometry buffer renderer is not supported but is required fo
• Active camera not set
• No camera defined
• At least one mesh is needed to create the nav mesh.
• Connect failed

AI-assisted analysis of BabylonJS/Babylon.js@0592b347b8 (2026-08-30). Data as JSON: /api/errors/de6c302acf2f5c18. Report an issue: GitHub.