Common Causes of TypeError: Cannot read properties of undefined (reading 'default') in Next.js
- Improper Module Import: This error often arises when an imported module does not export the property you're trying to access. This can happen when using ES6 module import syntax to get a CommonJS module or vice versa. If the module doesn't have a 'default' export, trying to access it will lead to this error.
- Component Misconfiguration: In some instances, components might be misconfigured or missing altogether within the project, especially if media or config files are moved or deleted, causing imports to resolve to 'undefined'.
- Incorrect Dynamic Imports: Next.js supports dynamic imports, but if a dynamic import is incorrectly specified or the module it points to doesn't exist or isn't resolved properly, the error might surface. This is common when there is an incorrect file path or syntax.
- Failure to Handle Asynchronous Data: Next.js often relies on data fetching methods that are asynchronous. If the asynchronous data has not yet been fetched or is null/undefined, and you try to access an object on that data prematurely, this error may occur.
- Improper Configuration in next.config.js: Some developers might experience this issue if they attempt to use custom setups that modify webpack settings beyond the default next.js configurations. If 'undefined' configurations or plugins are referenced during the build, it can lead to this error.
import React from 'react';
import MyComponent from './components/MyComponent'; // Ensure the path and export are correct
export default function Page() {
return <MyComponent />;
}
- Undefined Data Passed via Props: Props might be incorrectly passed in from a parent component, or the structure of the props might change unexpectedly, leaving some expected properties as undefined.
- Library Version Conflicts: Sometimes, if a library is updated but provides no backward compatibility or if incompatible versions are used together, you might end up expecting an object with a 'default' that isn't there.
- Server-Side Rendering Issues: Since Next.js is heavily reliant on SSR, any module or component that fails during server-side loading or which has a mismatch between server and client environments may cause this issue.
// Handling dynamic import with error handling
import dynamic from 'next/dynamic';
const MyDynamicComponent = dynamic(() => import('./MyComponent'), {
ssr: false, // Disable SSR if necessary
loading: () => <p>Loading...</p>,
});
export default function Page() {
return <MyDynamicComponent />;
}
- Misuse of Context or State: If using React Context or state improperly, especially without initializing with default values, accessing 'default' properties that don't exist could lead to this error.
