---
title: Disabling Staged ES6 Features
slug: develop/disabling-staged-es6-features
docTags: 
createdAt: 2025-03-11T07:03:32.131Z
---

Some ES6 features have not been finalized and may still contain bugs in the Chromium version(s) used by BrightSign. A crash may occur if your JavaScript application (or the framework code used to build the application) uses one of these features: For example, [this](https://bugs.chromium.org/p/v8/issues/detail?id=3923) is a known issue in Chromium version 45 that will cause a crash on BrightSign XTx44 and XDx34 players. 

To bypass such issues, you can disable all staged (i.e. experimental) ES6 features using the `disable-javascript-harmony-shipping` registry flag (which requires firmware version 7.1.49 or later). The following example shows how to set this registry flag using the [registry](docId\:tXWoOMbD2-u12dfegX7gA) JavaScript module (you can also use the [roRegistry](docId\:YTpSfntswYFMXx8PCqJLf) BrightScript object).

```text
var registryClass = require("@brightsign/registry");
var registry = new registryClass();


var systemClass = require("@brightsign/system");
var system = new systemClass();


registry.write("html", {js-disable-harmony-shipping:"1"}).then(
    function(){console.log("Write Successful");});


system.reboot()
```

Enabling this registry flag will limit the available JavaScript syntax. However, for ES6 features to be available, an application must be written to be compatible with both ES5 and ES6, so enabling this flag should not cause syntax errors or similar issues.