Here is the full log :

Notif Obj function (cutoff) {
		if (process.env.NODE_ENV === 'development') {
					winston.info('[notifications.prune] Removing expired notifications from the database.');
			}
			var     today = new Date(),
					numPruned = 0;
			if (!cutoff) {
					cutoff = new Date(today.getFullYear(), today.getMonth(), today.getDate() - 7);
			}
			var     cutoffTime = cutoff.getTime();
			async.parallel({
					"inboxes": function(next) {
							db.getSortedSetRange('users:joindate', 0, -1, function(err, uids) {
									if(err) {
											return next(err);
									}
									uids = uids.map(function(uid) {
											return 'uid:' + uid + ':notifications:unread';
										});
									next(null, uids);
							});
					},
					"expiredNids": function(next) {
							db.getSetMembers('notifications', function(err,nids) {
									async.filter(nids, function(nid, next) {
											db.getObjectField('notifications:' + nid, 'datetime', function(err, datetime) {
													if (parseInt(datetime, 10) < cutoffTime) {
															next(true);
													} else {
															next(false);
													}
											});
									}, function(expiredNids) {
											next(null, expiredNids);
									});
							});
					}
			}, function(err, results) {
					if(err) {
							if (process.env.NODE_ENV === 'development') {
									winston.error('[notifications.prune] Ran into trouble pruning expired notifications. Stack trace to follow.');
									winston.error(err.stack);
							}
							return;
					}
					async.eachSeries(results.expiredNids, function(nid, next) {
							db.sortedSetsScore(results.inboxes, nid, function(err, results) {
									if(err) {
											return next(err);
									}
									// If the notification is not present in any inbox, delete it altogether
									var     expired = results.every(function(present) {
													return present === null;
											});
									if (expired) {
											destroy(nid);
											numPruned++;
									}
									next();
							});
					}, function(err) {
							if (process.env.NODE_ENV === 'development') {
									winston.info('[notifications.prune] Notification pruning completed. ' + numPruned + ' expired notification' + (numPruned !== 1 ? 's' : '') + ' removed.');
							}
					});
			});
		}
D:\nuitInfo2013\forum\node_modules\mongodb\lib\mongodb\connection\base.js:242
		throw message;
			^
TypeError: undefined is not a function
	at Object.Notifications.init (D:\nuitInfo2013\forum\src\notifications.js:16:38)
	at D:\nuitInfo2013\forum\app.js:126:21
	at D:\nuitInfo2013\forum\src\upgrade.js:26:4
	at D:\nuitInfo2013\forum\src\database\mongo.js:309:4
	at D:\nuitInfo2013\forum\src\database\mongo.js:342:4
	at D:\nuitInfo2013\forum\node_modules\mongodb\lib\mongodb\collection\query.js:147:5
	at Cursor.nextObject (D:\nuitInfo2013\forum\node_modules\mongodb\lib\mongodb\cursor.js:733:5)
	at commandHandler (D:\nuitInfo2013\forum\node_modules\mongodb\lib\mongodb\cursor.js:713:14)
	at D:\nuitInfo2013\forum\node_modules\mongodb\lib\mongodb\db.js:1806:9
	at Server.Base._callHandler (D:\nuitInfo2013\forum\node_modules\mongodb\lib\
mongodb\connection\base.js:442:41)

I just deleted and cloned nodeBB again. I went through the installing process, I had one more step this time, it asked me to setup a new user for mongoDB since the install is fresh as well. It installed all schemas (I have done this the first time with --upgrade). I started nodeBB, and got the exact same error sadly.
Node version : 0.10.22 (x64)
MongoDB version : 2.4.8

Thank you for your time,
Azgarreth

Hello,

I have come to a dead end with this problem, as soon as I start nodeBB, it crashes with this error :

TypeError: undefined is not a function
    at Object.Notifications.init (D:\nuitInfo2013\forum\src\notifications.js:15:38)
    at D:\nuitInfo2013\forum\app.js:126:21
    at D:\nuitInfo2013\forum\src\upgrade.js:26:4
    at D:\nuitInfo2013\forum\src\database\mongo.js:309:4
    at D:\nuitInfo2013\forum\src\database\mongo.js:342:4
    at D:\nuitInfo2013\forum\node_modules\mongodb\lib\mongodb\collection\query.js:147:5
    at Cursor.nextObject (D:\nuitInfo2013\forum\node_modules\mongodb\lib\mongodb\cursor.js:733:5)
    at commandHandler (D:\nuitInfo2013\forum\node_modules\mongodb\lib\mongodb\cursor.js:713:14)
    at D:\nuitInfo2013\forum\node_modules\mongodb\lib\mongodb\db.js:1806:9
    at Server.Base._callHandler (D:\nuitInfo2013\forum\node_modules\mongodb\lib\mongodb\connection\base.js:442:41)

I am on Windows which may be one part of the problem.
Waiting for your answers, Best Regards,
Azgarreth