Fix the Broken ChatGPT Web Interface with a Custom User Script

Problem Analysis

In early August, a gray‑scale rollout of a new ChatGPT web version caused many users to see an error dialog saying "Oops, an error occurred! (Try again)" after starting a conversation. Opening the browser console reveals TypeError: n.toSorted is not a function. The OpenAI status page shows no service outage, indicating the issue is client‑side.

Testing on Chrome Canary (a newer build) works, confirming that the problem stems from an outdated browser. The new JavaScript bundle uses Array.prototype.toSorted(), a feature introduced in the ES2023 specification and only available in Chrome 110+ (or equivalent modern browsers).

Root Cause

Older Chrome versions or legacy browsers lacking support for Array.prototype.toSorted() cannot execute the updated ChatGPT code, leading to the console error and broken UI.

Solution Overview

When upgrading the browser is impossible, a polyfill can supply the missing method. Web developers typically use polyfills to back‑port new language features to older environments. Since ChatGPT itself did not include a polyfill, the author creates a custom user script that injects one.

User Script Basics

Three ways to customize a webpage are:

User style – inject custom CSS.

User script – inject custom JavaScript.

Browser extension – deeper integration.

For this issue, a user script offers the right balance of capability and simplicity.

Developing the User Script

The script needs to run on https://chatgpt.com/* and load a polyfill for Array.prototype.toSorted(). Tampermonkey, a popular user‑script manager, provides metadata fields to declare the script name, match pattern, and external resources.

// ==UserScript==
// @name         Polyfill ChatGPT
// @match        https://chatgpt.com/*
// @require      http://xxxxx.com/polyfill.js
// ==/UserScript==

console.log('Userscript Loaded.');

The @require line will later point to the actual polyfill file.

Preparing the Polyfill

The standard source for JavaScript polyfills is the core-js project ( github.com/zloirock/core-js). Using its core-js-builder tool, the author generates a bundle that includes the Array.prototype.toSorted implementation.

Installing the Script

In Chrome, click the Tampermonkey icon, choose “Create a new script”, replace the default content with the snippet above, and replace the placeholder URL in @require with the real polyfill URL (hosted on a personal site, GitHub Gist, or static server). Save the script.

After saving, the script appears in Tampermonkey’s “Installed userscripts” list.

Reload the ChatGPT page, start a new conversation, and the error disappears; the console no longer reports the missing method.

Open‑Source Reference

The complete script, polyfill source, build configuration, and usage instructions are available at github.com/UserScript/Polyfill-My-Browser. The repository also includes a README with troubleshooting tips for installing Tampermonkey.

Conclusion

By diagnosing the browser‑side incompatibility, locating the missing ES2023 feature, and deploying a targeted polyfill via a Tampermonkey user script, users of older browsers can regain full ChatGPT functionality without waiting for a browser upgrade.