As of October 30, 2025 this is the message that I get in Firefox console when running a Nuxt 2 project:

[_Vue DevTools v7 log_]

Vue DevTools v7 detected in your Vue2 project. v7 only supports Vue3 and will not work.

The legacy version of chrome extension that supports both Vue 2 and Vue 3 has been moved to https://chromewebstore.google.com/detail/vuejs-devtools/iaajmlceplecbljialhhkmedjlpdblhp

The legacy version of firefox extension that supports both Vue 2 and Vue 3 has been moved to https://addons.mozilla.org/firefox/addon/vue-js-devtools-v6-legacy

Please install and enable only the legacy version for your Vue2 app.

[_Vue DevTools v7 log_]

You will need to disable the v7 DevTools while running Nuxt 2 projects.