---
title: "4.0.1"
url: "https://www.cypress.io/releases/4-0-1"
description: "Bugfixes: 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…"
---

# 4.0.1

ReleasedReleased on February 6, 2020

**Bugfixes:**

-   Fixed a bug where Chromium could not be detected on macOS. Addresses [#6358](https://github.com/cypress-io/cypress/issues/6358).
    
-   Fixed bugs where Edge and Firefox Nightly could not be detected on macOS. Addresses [#6354](https://github.com/cypress-io/cypress/issues/6354) and [#6345](https://github.com/cypress-io/cypress/issues/6345).
    
-   Fixed a bug where 64-bit editions of Firefox could not be detected on Windows. Addresses [#6355](https://github.com/cypress-io/cypress/issues/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](https://github.com/cypress-io/cypress/issues/6369).
    
-   Fixed a bug where Cypress could crash with the message "cannot read property 'on' of undefined" while running Firefox. Addresses [#6356](https://github.com/cypress-io/cypress/issues/6356).
    
-   Corrected a link to the screenshot API documentation in the type definitions. Addresses [#6359](https://github.com/cypress-io/cypress/issues/6359).
    

**Misc:**

-   Updated the default preferences set on Firefox to hide update notifications and otherwise improve the Firefox experience. Addresses [#6346](https://github.com/cypress-io/cypress/issues/6346).