Received an error with invalid JSON from Parse: Cannot POST /classes/_User\n

[otymartin]

I'm using PFUser-Digits resource to authenticate parse users using Twitter's Digits API.

My parse server is hosted on App Engine with MongoLab database.

I get this error when trying to signup/login

Link to Swift File
Link to Cloud Code handling Authentication

2016-03-01 23:59:49.646 Bars[10323:15114219] [Error]: {
    code = 107;
    message = "Received an error with invalid JSON from Parse: Cannot POST /classes/_User\n";
} (Code: 141, Version: 1.12.0)
2016-03-01 23:59:49.647 Bars[10323:15113659] -[__NSCFDictionary length]: unrecognized selector sent to instance 0x7fe0adc33a10```

[otymartin]

SOLVED

In server.js, I neglected adding */parse * in serverURL: process.env.SERVER_URL || 'https://projectname.appspot.com/parse

because I thought it was taken care of here
app.use(process.env.PARSE_MOUNT_PATH || '/parse', parseServer);