I try to deploy my Mongo database in Mongolabs, everything works fine, and I create a new database. Please see my connectionstring.
public DbHelper()
Make Sure your auth db is set correctly.
I ran into this issue when I mentioned only the DB i wanted to connect to , and my auth db was different (other than admin db ).
The db-name in this line is considered as the auth DB .
new MongoClient("mongodb://username:password@ds011111.mongolab.com:11111/db-name?connect=replicaSet")
Then you can change the selected DB Later
mDb = mClient.GetDatabase(mongoDBName);