Edge

Microsoft Edge 126.0.2592.68 — Last version with support for Mutation Events Version Microsoft Edge 126.0.2592.68 is the last version of Edge that allows enabling support for Mutation Events, a deprecated DOM feature that was widely used in older web applications. Like Chrome, Edge is based on Chromium, and this version is aligned with Chromium 126, which still includes the hidden flag to enable Mutation Events manually. ...

If you encountered an error message like: Uncaught ReferenceError: MutationEvent is not defined or an unexpected error window related to MutationEvent when opening a page or system, then this article is for you. 📅 Updated: May 2025 This issue affects regular users, not just developers accessing old systems or web apps that still rely on outdated technology. The error started to appear more frequently in Google Chrome and Microsoft Edge from mid-2024 onwards. In this article, I explain: ...