The code in your Middleware or your Edge API Routes is using a feature from Node.js runtime.
However, the Edge Runtime does not support Node.js APIs and globals.
When running Next.js locally with next dev, your application will show in the console, and in your browser, which file is importing and using an unsupported module. This module must be avoided: either by not importing it, or by replacing it with a polyfill.
For example, you might replace the Node.js crypto module with the Web Crypto API.