this.store is undefined

[jondeandres]

I'm having a random error on radar/core/lib/resources/presence/presence_manager.js:249 calling this.store.userExists(userId).

Few times this.store.userExists(userId) is undefined, the complete backtrace is this:

TypeError: Cannot read property 'userExists' of undefined
1
at PresenceManager.setupExpiry (/home/deploy/www/moxrts/node_modules/radar/core/lib/resources/presence/presence_manager.js line 249 col 16)
if(this.store.userExists(userId)) {
2
at PresenceManager.handleOffline (/home/deploy/www/moxrts/node_modules/radar/core/lib/resources/presence/presence_manager.js line 228 col 10)
this.setupExpiry(userId, userType);
3
at PresenceManager.processRedisEntry (/home/deploy/www/moxrts/node_modules/radar/core/lib/resources/presence/presence_manager.js line 209 col 10)
this.handleOffline(clientId, userId, userType, message.explicit);
4
at Resource.Presence.redisIn (/home/deploy/www/moxrts/node_modules/radar/core/lib/resources/presence/index.js line 88 col 16)
this.manager.processRedisEntry(message);
5
at Server.handleMessage (/home/deploy/www/moxrts/node_modules/radar/server/server.js line 102 col 25)
this.channels[name].redisIn(data);
6
at emitTwo (events.js line 111 col 20)
7
at RedisClient.emit (events.js line 191 col 7)
8
at RedisClient.return_reply (/home/deploy/www/moxrts/node_modules/radar/node_modules/persistence/node_modules/redis/index.js line 694 col 22)
this.emit("message", reply[1].toString(), reply[2]); // channel, message
9
at ReplyParser.<anonymous> (/home/deploy/www/moxrts/node_modules/radar/node_modules/persistence/node_modules/redis/index.js line 321 col 14)
self.return_reply(reply);
10
at emitOne (events.js line 96 col 13)
11
at ReplyParser.emit (events.js line 188 col 7)

radar version: 0.10.1

Any suggestion about what can be causing this? Thanks