---
title: Javascript-SDK - 6.6.1
slug: feature-experimentation/release-notes/javascript-sdk-6-6-1
docTags: 
createdAt: 2026-10-04T12:21:30.000Z
---

## \[6.6.1] - September 18, 2026

### Bug Fixes

- Use an updated datafile cache key so the SDK no longer reads a stale or malformed datafile persisted by an older SDK version ([#1175](https://github.com/optimizely/javascript-sdk/pull/1175))

[https://github.com/optimizely/javascript-sdk/releases/tag/v6.6.1](https://github.com/optimizely/javascript-sdk/releases/tag/v6.6.1)