# Cypress v4.0.1 — Release & Upgrade Intelligence
- **Product:** Cypress (https://www.cypress.io)
- **Version:** v4.0.1
- **Released:** Feb 08, 2020
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/cypress/updates/v4.0.1/

## Executive Summary (TL;DR)
Cypress v4.0.1. Source highlight: Fixed a bug where Chromium could not be detected on macOS. Addresses #6358.

## Improvements
- Updated the default preferences set on Firefox to hide update notifications and otherwise improve the Firefox experience. Addresses #6346.

## Bug Fixes
- Fixed a bug where Chromium could not be detected on macOS. Addresses #6358.
- Fixed bugs where Edge and Firefox Nightly could not be detected on macOS. Addresses #6354 and #6345.
- Fixed a bug where 64-bit editions of Firefox could not be detected on Windows. Addresses #6355.
- Fixed a bug where video recordings of Firefox would omit all frames from before the last cross-domain navigation of the test. Addresses #6369.
- Fixed a bug where Cypress could crash with the message "cannot read property 'on' of undefined" while running Firefox. Addresses #6356.