Troubleshooting ​

See Rollup's troubleshooting guide for more information too.

If the suggestions here don't work, please try posting questions on GitHub Discussions or in the #help channel of Vite Land Discord.

CLI ​

Error: Cannot find module 'C:\foo\bar&baz\vite\bin\vite.js' ​

The path to your project folder may include &, which doesn't work with npm on Windows (npm/cmd-shim#45).

You will need to either:

• Switch to another package manager (e.g. pnpm, yarn)
• Remove & from the path to your project

Config ​

This package is ESM only ​

When importing a ESM only package by require, the following error happens.

Failed to resolve "foo". This package is ESM only but it was tried to load by require.

Error [ERR_REQUIRE_ESM]: require() of ES Module /path/to/dependency.js from /path/to/vite.config.js not supported. Instead change the require of index.js in /path/to/vite.config.js to a dynamic import() which is available in all CommonJS modules.

In Node.js <=22, ESM files cannot be loaded by require by default.

While it may work using --experimental-require-module, or Node.js >22, or in other runtimes, we still recommend converting your config to ESM by either:

• adding "type": "module" to the nearest package.json
• renaming vite.config.js/vite.config.ts to vite.config.mjs/vite.config.mts

Dev Server ​

Requests are stalled forever ​

If you are using Linux, file descriptor limits and inotify limits may be causing the issue. As Vite does not bundle most of the files, browsers may request many files which require many file descriptors, going over the limit.

To solve this:

• Increase file descriptor limit by ulimit

  shell

  # Check current limit
  $ ulimit -Sn
  # Change limit (temporary)
  $ ulimit -Sn 10000 # You might need to change the hard limit too
  # Restart your browser

• Increase the following inotify related limits by sysctl

  shell

  # Check current limits
  $ sysctl fs.inotify
  # Change limits (temporary)
  $ sudo sysctl fs.inotify.max_queued_events=16384
  $ sudo sysctl fs.inotify.max_user_instances=8192
  $ sudo sysctl fs.inotify.max_user_watches=524288

If the above steps don't work, you can try adding DefaultLimitNOFILE=65536 as an un-commented config to the following files:

• /etc/systemd/system.conf
• /etc/systemd/user.conf

For Ubuntu Linux, you may need to add the line * - nofile 65536 to the file /etc/security/limits.conf instead of updating systemd config files.

Note that these settings persist but a restart is required.

Alternatively, if the server is running inside a VS Code devcontainer, the request may appear to be stalled. To fix this issue, see Dev Containers / VS Code Port Forwarding.

Network requests stop loading ​

When using a self-signed SSL certificate, Chrome ignores all caching directives and reloads the content. Vite relies on these caching directives.

To resolve the problem use a trusted SSL cert.

See: Cache problems, Chrome issue

macOS ​

You can install a trusted cert via the CLI with this command:

security add-trusted-cert -d -r trustRoot -k ~/Library/Keychains/login.keychain-db your-cert.cer

Or, by importing it into the Keychain Access app and updating the trust of your cert to "Always Trust."

431 Request Header Fields Too Large ​

When the server / WebSocket server receives a large HTTP header, the request will be dropped and the following warning will be shown.

Server responded with status code 431. See https://vite.dev/guide/troubleshooting.html#_431-request-header-fields-too-large.

This is because Node.js limits request header size to mitigate CVE-2018-12121.

To avoid this, try to reduce your request header size. For example, if the cookie is long, delete it. Or you can use --max-http-header-size to change max header size.

Dev Containers / VS Code Port Forwarding ​

If you are using a Dev Container or port forwarding feature in VS Code, you may need to set the server.host option to 127.0.0.1 in the config to make it work.

This is because the port forwarding feature in VS Code does not support IPv6.

See #16522 for more details.

HMR ​

Vite detects a file change but the HMR is not working ​

You may be importing a file with a different case. For example, src/foo.js exists and src/bar.js contains:

import './Foo.js' // should be './foo.js'

Related issue: #964

Vite does not detect a file change ​

If you are running Vite with WSL2, Vite cannot watch file changes in some conditions. See server.watch option.

A full reload happens instead of HMR ​

If HMR is not handled by Vite or a plugin, a full reload will happen as it's the only way to refresh the state.

If HMR is handled but it is within a circular dependency, a full reload will also happen to recover the execution order. To solve this, try breaking the loop. You can run vite --debug hmr to log the circular dependency path if a file change triggered it.

Build ​

Built file does not work because of CORS error ​

If the HTML file output was opened with file protocol, the scripts won't run with the following error.

Access to script at 'file:///foo/bar.js' from origin 'null' has been blocked by CORS policy: Cross origin requests are only supported for protocol schemes: http, data, isolated-app, chrome-extension, chrome, https, chrome-untrusted.

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at file:///foo/bar.js. (Reason: CORS request not http).

See Reason: CORS request not HTTP - HTTP | MDN for more information about why this happens.

You will need to access the file with http protocol. The easiest way to achieve this is to run npx vite preview.

No such file or directory error due to case sensitivity ​

If you encounter errors like ENOENT: no such file or directory or Module not found, this often occurs when your project was developed on a case-insensitive filesystem (Windows / macOS) but built on a case-sensitive one (Linux). Please make sure that the imports have the correct casing.

Failed to fetch dynamically imported module error ​

TypeError: Failed to fetch dynamically imported module

This error occurs in several cases:

• Version skew
• Poor network conditions
• Browser extensions blocking requests

Version skew ​

When you deploy a new version of your application, the HTML file and the JS files still reference old chunk names that were deleted in the new deployment. This happens when:

1. Users have an old version of your app cached in their browser
2. You deploy a new version with different chunk names (due to code changes)
3. The cached HTML tries to load chunks that no longer exist

If you are using a framework, refer to their documentation first as it may have a built-in solution for this problem.

To resolve this, you can:

• Keep old chunks temporarily: Consider keeping the previous deployment's chunks for a period to allow cached users to transition smoothly.
• Use a service worker: Implement a service worker that will prefetch all the assets and cache them.
• Prefetch the dynamic chunks: Note that this does not help if your HTML file is cached by the browser due to Cache-Control headers.
• Implement a graceful fallback: Implement error handling for dynamic imports to reload the page when chunks are missing. See Load Error Handling for more details.

Poor network conditions ​

This error may occur in unstable network environments. For example, when the request fails due to network errors or server downtime.

Note that you cannot retry the dynamic import due to browser limitations (whatwg/html#6768).

Browser extensions blocking requests ​

The error may also occur if the browser extensions (like ad-blockers) are blocking that request.

It might be possible to work around by selecting a different chunk name by build.rollupOptions.output.chunkFileNames, as these extensions often block requests based on file names (e.g. names containing ad, track).

Optimized Dependencies ​

Outdated pre-bundled deps when linking to a local package ​

The hash key used to invalidate optimized dependencies depends on the package lock contents, the patches applied to dependencies, and the options in the Vite config file that affects the bundling of node modules. This means that Vite will detect when a dependency is overridden using a feature as