remix-run/remix · error · CliError

RMX_ROUTE_MAP_LOADER_INVALID_JSON

RMX_ROUTE_MAP_LOADER_INVALID_JSON

Error message

Route-map loader returned invalid JSON

What it means

The route-map loader subprocess ran successfully but printed content that is not valid JSON on the channel the CLI parses. Anything app/routes.ts (or its imports) writes to stdout during loading corrupts the JSON handshake. The CLI therefore cannot extract the route map.

Source

Thrown at packages/cli/src/lib/errors.ts:113

    title: 'Could not find a project root',
    fix: 'Run this command inside a Remix project.',
  },
  remixConfigNotFound: {
    code: 'RMX_CONFIG_NOT_FOUND',
    title: 'Remix configuration not found',
    fix: 'Check the --config path and try again.',
  },
  remoteSkillDataMissing: {
    code: 'RMX_REMOTE_SKILL_DATA_MISSING',
    title: 'Could not find remote Remix skill data',
  },
  routeMapLoaderFailed: {
    code: 'RMX_ROUTE_MAP_LOADER_FAILED',
    title: 'Route-map loader failed',
    fix: 'Check app/routes.ts and make sure it exports a named `routes` value with a valid route map.',
  },
  routeMapLoaderInvalidJson: {
    code: 'RMX_ROUTE_MAP_LOADER_INVALID_JSON',
    title: 'Route-map loader returned invalid JSON',
    fix: 'Check app/routes.ts and make sure route-map loading does not write extra output.',
  },
  routeMapLoaderSignal: {
    code: 'RMX_ROUTE_MAP_LOADER_SIGNAL',
    title: 'Route-map loader exited from a signal',
    fix: 'Check app/routes.ts for side effects or runtime issues and try again.',
  },
  routeOwnerPlanUnresolved: {
    code: 'RMX_ROUTE_OWNER_PLAN_UNRESOLVED',
    title: 'Could not resolve a route owner plan',
  },
  routesFileNotFound: {
    code: 'RMX_ROUTES_FILE_NOT_FOUND',
    title: 'Could not find app/routes.ts',
    fix: 'Run this command inside a Remix app that has app/routes.ts.',
  },
  targetDirectoryNotEmpty: {

View on GitHub (pinned to 9696913134)

Solutions

1. Remove console.log/process.stdout.write calls from app/routes.ts and any modules it imports at load time.
2. Move logging into route handlers or lazy-loaded modules instead of module scope.
3. If you need debug output while authoring routes, write to stderr or a file instead of stdout.
4. Re-run the CLI command to confirm the JSON parses.

Example fix

// before
// app/routes.ts
console.log('building routes', config)
export const routes = config

// after
// app/routes.ts
export const routes = [
  { path: '/', file: 'routes/index.tsx' },
]

// Before loading, ensure route modules don't write to stdout
let src = await readFile('app/routes.ts', 'utf8')
if (/console\.log|process\.stdout\.write/.test(src)) {
  throw new Error('route config writes to stdout')
}

try {
  let map = await loadRouteMap()
} catch (error) {
  if (error.code === 'RMX_ROUTE_MAP_LOADER_INVALID_JSON') {
    // strip stdout writes from route config imports
  }
}

When it happens

Trigger: app/routes.ts or one of its imports calling console.log/process.stdout.write at module scope; a dependency printing a banner; output buffering interleaving with the loader's JSON payload.

Common situations: Debug console.log statements left in route config files, noisy third-party imports (analytics SDKs, debug libraries), or polyfills that print during import.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• RMX_ROUTE_MAP_LOADER_INVALID_JSON
• hmr must be provided
• hmr requires watch mode
• Missing app/routes.ts path.
• Route module ${routesFile} must export a named "routes" valu

AI-assisted analysis of remix-run/remix@9696913134 (2026-08-27). Data as JSON: /api/errors/ce1bea87b109e493. Report an issue: GitHub.