Unitech/pm2 · critical · Error

Could not _load() the script

Error message

Could not _load() the script

What it means

ProcessContainerFork.js is the wrapper process PM2 forks for each app instance. It reads process.env.pm_exec_path and loads the user's script via import() (ESM) or module._load() (CJS). If pm_exec_path is missing or falsy there is no script to run, so the forked wrapper throws.

Source

Thrown at lib/ProcessContainerFork.js:35

if (process.connected &&
    process.send &&
    process.versions &&
    process.versions.node)
  process.send({
    'node_version': process.versions.node
  });

// Require the real application
if (process.env.pm_exec_path) {
  if (ProcessUtils.isESModule(process.env.pm_exec_path) === true) {
    import(url.pathToFileURL(process.env.pm_exec_path));
  }
  else
    require('module')._load(process.env.pm_exec_path, null, true);
}
else
  throw new Error('Could not _load() the script');

// Change some values to make node think that the user's application
// was started directly such as `node app.js`
process.mainModule = process.mainModule || {};
process.mainModule.loaded = false;
require.main = process.mainModule;

View on GitHub (pinned to 31adee8048)

Solutions

1. Delete and re-add the affected app: `pm2 delete <app>` then `pm2 start <entry>`.
2. Clear and regenerate the dump: stop everything, `pm2 save` once after a clean start.
3. Ensure your ecosystem/script path resolves to an existing file before starting.

if (!process.env.pm_exec_path) {
  console.error('pm_exec_path missing; refusing to fork a wrapper with no script');
  process.exit(1);
}

try {
  pm2.start(app, cb);
} catch (e) {
  if (/Could not _load\(\) the script/.test(e.message)) {
    pm2.delete(app.name, () => pm2.start(app, cb)); // reset and re-add
  } else { throw e; }
}

When it happens

Trigger: PM2 forks a worker but the environment was not seeded with pm_exec_path — typically an internally inconsistent state: corrupted dump file, a process resurrected from an older PM2 version, or programmatic launch with an incomplete env.

Common situations: Resurrecting a dump.json saved by an incompatible/older PM2; manually constructed process envs; an app entry whose path failed to resolve before fork.

Related errors

• No app_name defined

AI-assisted analysis of Unitech/pm2@31adee8048 (2026-08-13). Data as JSON: /api/errors/4a616b9acc3aa806. Report an issue: GitHub.