Cannot access Node.js based website hosted in Plesk: EADDRINUSE

Symptoms

Unable to access website with Node.js application:

CONFIG_TEXT: Application has thrown an uncaught exception and is terminated:
Error: Listen EADDRINUSE

Cause

The other process listens on the port specified for Node.js application.

Resolution

Note: if you don't have administrative access to Plesk server via RDP, contact your hosting provider regarding the issue

1. Log in to Plesk server using RDP and find an unused port:

   C:\> netstat -a -b

2. Log in to Plesk and navigate to Subscriptions > example.com > Node.js .

3. Click edit oppositely to "Application Startup File", for example:
   

4. Specify the port chosen on the step 1, for example:

   CONFIG_TEXT: ...
   port = process.env.PORT || 3031,
   ...
   app.set('port', 3031);
   ...

   Video tutorial: