I had this exact same problem a couple of days ago and couldn't figure it out. Haven't managed to fix the problem properly but this works as a temporary fix:

Go up one level (above app.js) and do npm install ejs. It will create a new node_modules folder and Express should find the module then.

Install express locally

(npm install express while in the project's root directory)

Your project depends on both express and ejs, so you should list them both as dependencies in your package.json.

That way when you run npm install in you project directory, it'll install both express and ejs, so that var express = require('express') will be the local installation of express (which knows about the ejs module that you installed locally) rather than the global one, which doesn't.

In general it's a good idea to explicitly list all dependencies in your package.json even though some of them might already be globally installed, so you don't have these types of issues.

I had the same issue. Once I set environment variable NODE_PATH to the location of my modules (/usr/local/node-v0.8.4/node_modules in my case) the problem went away. P.S. NODE_PATH accepts a colon separated list of directories if you need to specify more than one.