vitejs/vite · error · Error

[module runner] Failed to load "${url}"${importer ? ` import

Error message

[module runner] Failed to load "${url}"${importer ? ` imported from ${importer}` : ''}

What it means

Thrown in directRequest when the fetched module result has null/undefined code. The module runner successfully fetched metadata for the URL (the transport returned a result), but the actual code field is missing. This means the server couldn't provide the transformed source for the requested module — the file doesn't exist, couldn't be read, failed to transform, or was otherwise unavailable.

Source

Thrown at packages/vite/src/module-runner/runner.ts:363

      if (dep[0] === '.') {
        dep = posixResolve(posixDirname(url), dep)
      }
      return request(dep, { isDynamicImport: true })
    }

    if ('externalize' in fetchResult) {
      const { externalize } = fetchResult
      this.debug?.('[module runner] externalizing', externalize)
      const exports = await this.evaluator.runExternalModule(externalize)
      mod.exports = exports
      return exports
    }

    const { code, file } = fetchResult

    if (code == null) {
      const importer = callstack[callstack.length - 2]
      throw new Error(
        `[module runner] Failed to load "${url}"${
          importer ? ` imported from ${importer}` : ''
        }`,
      )
    }

    const createImportMeta =
      this.options.createImportMeta ?? createDefaultImportMeta

    const modulePath = cleanUrl(file || moduleId)
    // disambiguate the `<UNIT>:/` on windows: see nodejs/node#31710
    const href = posixPathToFileHref(modulePath)
    const meta = await createImportMeta(modulePath)
    const exports = Object.create(null)
    Object.defineProperty(exports, Symbol.toStringTag, {
      value: 'Module',
      enumerable: false,
      configurable: false,

View on GitHub (pinned to 89620f09af)

Solutions

Verify the module URL/path exists and is resolvable by the Vite dev server — check for typos, wrong extensions, or missing files.
If importing a virtual module (e.g., virtual:my-plugin), ensure the plugin that provides it is loaded and its resolveId/load hooks are correct.
Debug the transport's fetchModule response to confirm the server is returning code; log the fetch result before the error point.
Check the Vite dev server logs for transform errors on the specific module.

Defensive patterns

Strategy: try-catch

Validate before calling

// Validate the module URL is resolvable before importing
async function validateModuleExists(server, url) {
  // use the server's transformRequest or module graph to check
  const mod = server.moduleGraph.getModuleById(url)
  if (!mod) {
    console.warn(`Module ${url} not found in module graph — import may fail`)
  }
  return !!mod
}

Type guard

function isValidModuleUrl(url: string): boolean {
  // basic validation: non-empty, valid path
  return typeof url === 'string' && url.length > 0 && !url.includes('\0null')
}

Try / catch

try {
  await runner.import(url)
} catch (e) {
  if (e.message.includes('Failed to load')) {
    console.error(`Module not found or transform failed: ${url}`)
    console.error('Check: file exists, virtual module plugin is loaded, no transform errors')
  }
  throw e
}

Prevention

Verify module paths exist and are correct before importing in SSR code.
Ensure all virtual module plugins are properly configured and loaded.
Check Vite dev server logs for transform errors on imported modules.
Implement custom transport fetchModule logging to inspect server responses during development.

When it happens

Trigger: Importing a URL that doesn't resolve to any file on the server. A transform error during fetchModule that results in a response with no code. A transport that returns a malformed fetch result (missing code field). Importing a virtual module that the server doesn't handle.

Common situations: Importing a non-existent module path in SSR code. A file was deleted or renamed but code still imports it. A Vite plugin that should provide a virtual module via resolveId/load is missing or misconfigured. Network or serialization issues in custom transports that drop the code field.

Related errors

AI-assisted analysis of vitejs/vite@89620f09af (2026-08-03). Data as JSON: /data/errors/0edd474c7d15ba47.json. Report an issue: GitHub.