Node.js Port 3000 already in use but it actually isn't?
<p>I have been working with a node.js project for a few weeks and it has been working great. Usually, I use <code>npm start</code> to run my app and view it in a browser on localhost, port 3000.</p>

<p>Today, I started to get the following error while using npm start:</p>

<pre class="lang-none prettyprint-override"><code>Server started on port 3000                                                                                                                                                                                         
Port 3000 is already in use 
</code></pre>

<p>I have checked the resource monitor and I have no other process running on port 3000. Why would I be getting this error message?</p>

<p>In my app.js I have the following code to set the port...is this incorrect? It worked fine before so I'm not sure what I am doing wrong.</p>

<pre><code>// Set Port
app.set('port', (process.env.PORT || 3000));
app.listen(app.get('port'), function() {
    console.log('Server started on port '+app.get('port'));
});
</code></pre>

<p>Thanks for the help! </p>

<hr>

<h2>EDIT:</h2>

<p>I have tried running netstat and TCPView to check what process is using the port, but there is nothing using that port. I also tried restarting my laptop but I still get the same error. </p>