After my first test setup with redis ended with the dreaded "cannot GET /" with no further error messages I decided to start over with Mongo. Unfortunately it appears I get the same error message with a clean install.

CentOS Linux release 7.2.1511
mongodb-org-server-3.2.4-1.el7.x86_64
Node v0.12.12

Log:

Clustering enabled: Spinning up 1 process(es).

10/3 04:55 [20982] - info: Time: Thu Mar 10 2016 04:55:56 GMT-0500 (EST)
10/3 04:55 [20982] - info: Initializing NodeBB v1.0.0
10/3 04:55 [20982] - info: [database] Checking database indices.
10/3 04:56 [20982] - warn: [socket.io] Clustering detected, you are advised to configure Redis as a websocket store.

10/3 04:56 [20982] - warn: [plugins/load] The following plugins may not be compatible with your version of NodeBB. This may cause unintended behaviour or crashing. In the event of an unresponsive NodeBB caused by this plugin, run `./nodebb reset -p PLUGINNAME` to disable it.
  * nodebb-theme-persona
  * nodebb-plugin-mentions

10/3 04:56 [20982] - info: NodeBB Ready
10/3 04:56 [20982] - info: Enabling 'trust proxy'
10/3 04:56 [20982] - info: NodeBB is now listening on: 0.0.0.0:4567

config.json:

{
    "url": "http://localhost:4567",
    "secret": "thereusedtobeasecrethere",
    "database": "mongo",
    "mongo": {
        "host": "127.0.0.1",
        "port": "27017",
        "username": "nodebb",
        "password": "thereusedtobeapasswordhere",
        "database": "nodebb"
    }
}

Is there in general anything I can do to debug the "cannot GET /" error?

#edit: The forum works in dev mode after a clean install (./nodebb dev)