TypeError: Cannot set property 'wikipages_count' of undefined

[Muhammad Al-Syrwan]

i  have this error when starting the server 

/home/mhdsyrwan/node_tests/microcommunity/node_modules/mongodb/lib/mongodb/connection/server.js:428

        throw err;

              ^

TypeError: Cannot set property 'wikipages_count' of undefined

    at _.extend (/home/mhdsyrwan/node_tests/microcommunity/node_modules/underscore/underscore.js:642:19)

    at Array.forEach (native)

    at _.each._.forEach (/home/mhdsyrwan/node_tests/microcommunity/node_modules/underscore/underscore.js:76:11)

    at Function._.extend (/home/mhdsyrwan/node_tests/microcommunity/node_modules/underscore/underscore.js:640:5)

    at exports.fetch (/home/mhdsyrwan/node_tests/microcommunity/providers/users-provider.coffee:23:13)

    at exports.fetch_user_data (/home/mhdsyrwan/node_tests/microcommunity/providers/users-provider.coffee:54:22)

    at Collection.count (/home/mhdsyrwan/node_tests/microcommunity/node_modules/mongodb/lib/mongodb/collection.js:557:5)

    at g (events.js:185:14)

    at EventEmitter.emit (events.js:115:20)

    at Db._callHandler (/home/mhdsyrwan/node_tests/microcommunity/node_modules/mongodb/lib/mongodb/db.js:1396:25)

[Muhammad Al-Syrwan]

sorry .. the problem is solved after resetting the database