---
title: X
description: Opening a Core Web Vitals monitor showed "Application Error — Cannot read properties of undefined (reading 'short')" instead of the page. The metric cards had…
canonical: https://watchfor.io/changelog/2026-09-11-core-web-vitals-page-crash
---

[All updates](/changelog/page/3#2026-09-11-core-web-vitals-page-crash) 🐛 Fixed Sep 11, 2026 · v 7.6.6

# Core Web Vitals monitor pages open again

Opening a Core Web Vitals monitor showed "Application Error — Cannot read properties of undefined (reading 'short')" instead of the page. The metric cards had started showing Interaction to Next Paint before its definition existed, and the page fell over on the missing entry. INP is now defined with web.dev's thresholds, and a missing metric definition is caught before a release rather than by you.

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Canonical page: https://watchfor.io/changelog/2026-09-11-core-web-vitals-page-crash · Site guide: https://watchfor.io/llms.txt