Error occurred prerendering page in Next.js: Causes and How to Fix

Check for Data Dependencies

• Ensure that any data the page requires is available and correctly fetched during the build process.

 

• Review `getStaticProps` or `getStaticPaths` to ensure they do not fail or return undefined data.

export async function getStaticProps() {
  // Fetch necessary data
  return {
    props: {
      data: fetchedData || null, // Ensure fallback for undefined data
    },
  };
}

Manage Dynamic Imports

• Ensure that any component used with dynamic imports is loaded correctly during prerendering.

 

• Utilize optional chaining or default exports when dealing with dynamic imports to prevent undefined errors.

// Dynamic import with optional chaining
const DynamicComponent = dynamic(() => import('../components/DynamicComponent').then(mod => mod?.default))

Use Environment Variables Correctly

• Ensure all required environment variables are correctly set and accessible during the build process.

 

• Utilize Next.js environment variable support by prefixing with `NEXT_PUBLIC_` for variables needed client-side.

// Access environment variables
const apiUrl = process.env.NEXT_PUBLIC_API_URL;

Verify Third-Party API Calls

• Ensure all third-party API calls used during prerendering are functioning as expected and have error handling in place.

 

• Consider wrapping API calls in try-catch blocks to gracefully handle potential errors.

export async function getStaticProps() {
  try {
    const res = await fetch('https://api.example.com/data');
    const data = await res.json();
    return { props: { data } };
  } catch (error) {
    console.error('API call failed:', error);
    return { props: { data: null } };
  }
}

Optimize Image Usage

• When using Next.js Image optimization, ensure images are correctly accessible during the build phase.

 

• Check image URLs and paths for correctness.

import Image from 'next/image';

export default function Page() {
  return <Image src="/images/pic.jpg" width={500} height={300} alt="Picture" />;
}

Debugging Techniques

• Use the `next build` command with debugging flags to gather more insights into the prerendering error.

 

• Analyze console errors and stack traces to pinpoint issues in your code.

next build --verbose

Utilize Proper Fallback Strategies

• Ensure that your `getStaticProps` and `getStaticPaths` functions return proper fallback strategies to handle missing or error-prone data.

 

• Consider using `fallback: true` or `fallback: blocking` in `getStaticPaths` for handling unknown paths gracefully.

export async function getStaticPaths() {
  return {
    paths: [],
    fallback: 'blocking', // Fallback strategy for handling unknown paths
  };
}

Update and Audit Dependencies

• Regularly update your project's dependencies to ensure compatibility with the latest Next.js features and bug fixes.

 

• Audit dependent libraries to detect issues or deprecated features that might affect prerendering.

npm update
npm audit fix