Why is PM2 not launching my Node process?

Previously I have had success implementing PM2, but not currently.

My node app does run just fine if I start it manually, but nothing I do gets it to run via PM2, even though PM2 appears to be starting it up. Here's what I mean:

If I run pm2 start server/index.js, the response in the terminal reads:

$ pm2 start server/index.js
[PM2] Spawning PM2 daemon with pm2_home=c:\pm2_system\.pm2
[PM2] PM2 Successfully daemonized
[PM2] Starting D:\Program Files\nodeApps\service-management-api\server\index.js in fork_mode (1 instance)
[PM2] Done.*

Then the terminal prints out a table with App info. It doesn't look pretty pasted here so I'll list it out:

App Name: index
id: 0
version: 1.0.0
mode: fork
pid: 8984
status: online
restart: 0
update 0s
cpu: 0% 
mem: 26.0 MB
user: ME
watching: disabled

It appears that the node process should be running. But if I immediately enter pm2 list it shows no processes running. If I enter pm2 stop index, it says:

$ pm2 stop index
[PM2] Spawning PM2 daemon with pm2_home=c:\pm2_system\.pm2
[PM2] PM2 Successfully daemonized
[PM2][ERROR] Process index not found

Alternatively, if I try using ecosystem.config.js in the commands, I get similar results. Here are the commands tried:

pm2 reload ecosystem.config.js
pm2 start ecosystem.config.js

Example result of running those commmands:

$ pm2 start ecosystem.config.js
[PM2] Spawning PM2 daemon with pm2_home=c:\pm2_system\.pm2
[PM2] PM2 Successfully daemonized
[PM2][WARN] Applications sm_api not running, starting...
[PM2] App [sm_api] launched (2 instances)

And CLI prints table showing two instances with status "online" and watching "enabled". And yet, app isn't running (when tested from browser) and "pm2 show " returns:

[PM2] Spawning PM2 daemon with pm2_home=c:\pm2_system\.pm2
[PM2] PM2 Successfully daemonized
[PM2][WARN] <app name> doesn't exist

Any clues what's gone awry with my pm2?

Heres my ecosystem.config.js file:

module.exports = {
  apps : [{
    name: 'sm_api',
    script: 'server/index.js',
    "log_date_format"  : "YYYY-MM-DD HH:mm Z",

    // Options reference: https://pm2.io/doc/en/runtime/reference/ecosystem-file/
    args: 'one two',
    instances: 'max',
    error_file : "C:\\pm2_system\\.pm2\\logs\\sm-api-error",
    out_file: "C:\\pm2_system\\.pm2\\logs\\sm-api-out",
    autorestart: true,
    watch: "../",
    max_restarts: 10,
    max_memory_restart: '1G',
    env: {
      NODE_ENV: 'development'
    },
    env_production: {
      NODE_ENV: 'production'
    },
    exec_mode: 'cluster'
  }],
};

Running in Windows Server 2012 environment. Note that I intend to add pm2-windows-service package after I get pm2 working.

Solution

Ok, I got the answer after posting an issue to the pm2 github issues page.

Sharing it here in case anyone else finds themselves in this situation:

https://github.com/Unitech/pm2/issues/4113

(Basically pm2 3.2.5 introduced a bug that causes this issue in Windows. My dev install was 3.2.4. The issue was resolved by reverting to 3.2.4 in production. Simple process, see instructions at link above.)