After the app started and Mongo connected properly, some sort of service interruption happened. Mongo attempted to throw a clean error, but failed and the var message was undefined.

Node v12 running on Ubuntu 14 LT.

/home/ubuntu/strogsvr/node_modules/mongodb-core/lib/error.js:22

        super(message.message || message.errmsg || message.$err || 'n/a');

                      ^

TypeError: Cannot read property 'message' of undefined

    at new MongoError (/home/ubuntu/strogsvr/node_modules/mongodb-core/lib/error.js:22:23)

    at new MongoNetworkError (/home/ubuntu/strogsvr/node_modules/mongodb-core/lib/error.js:60:5)

    at TLSSocket.err (/home/ubuntu/strogsvr/node_modules/mongodb-core/lib/connection/connect.js:287:16)

    at Object.onceWrapper (events.js:313:30)

    at emitNone (events.js:106:13)

    at TLSSocket.emit (events.js:208:7)

    at TLSSocket.Socket._onTimeout (net.js:422:8)

    at ontimeout (timers.js:498:11)

    at tryOnTimeout (timers.js:323:5)

    at Timer.listOnTimeout (timers.js:290:5)

Program node ./app.js exited with code 1