I try to use method collection.Insert( ) and I have this problem:

NotImplementedException: recursionPolicy != NoRecursion not currently implemented
System.Threading.ReaderWriterLockSlim..ctor (LockRecursionPolicy recursionPolicy)
MongoDB.Bson.Serialization.BsonSerializer..cctor ()
Rethrow as TypeInitializationException: An exception was thrown by the type initializer for MongoDB.Bson.Serialization.BsonSerializer
MongoDB.Driver.Internal.MongoConnection.RunCommandAs[CommandResult] (System.String databaseName, QueryFlags queryFlags, MongoDB.Driver.CommandDocument command, Boolean throwOnError)
MongoDB.Driver.MongoServerInstance.Ping (MongoDB.Driver.Internal.MongoConnection connection)
Rethrow as MongoConnectionException: Unable to connect to server localhost:27017: An exception was thrown by the type initializer for MongoDB.Bson.Serialization.BsonSerializer.
MongoDB.Driver.Internal.DirectMongoServerProxy.Connect (TimeSpan timeout, MongoDB.Driver.ReadPreference readPreference)
MongoDB.Driver.Internal.DirectMongoServerProxy.ChooseServerInstance (MongoDB.Driver.ReadPreference readPreference)
MongoDB.Driver.MongoServer.AcquireConnection (MongoDB.Driver.ReadPreference readPreference)
MongoDB.Driver.MongoCollection.InsertBatch (System.Type nominalType, IEnumerable documents, MongoDB.Driver.MongoInsertOptions options)
MongoDB.Driver.MongoCollection.Insert (System.Type nominalType, System.Object document, MongoDB.Driver.MongoInsertOptions options)
MongoDB.Driver.MongoCollection.Insert (System.Type nominalType, System.Object document)
MongoDB.Driver.MongoCollection.Insert[Task] (AssemblyCSharp.Task document)
MongoDB.Driver.MongoCollection`1[AssemblyCSharp.Task].Insert (AssemblyCSharp.Task document)
AssemblyCSharp.Dal.CreateTask (AssemblyCSharp.Task task) (at Assets/AdminAds/Scripts/Dal.cs:66)
AssemblyCSharp.Dal..ctor () (at Assets/AdminAds/Scripts/Dal.cs:25)
AddNew.ClickAdd () (at Assets/AdminAds/Scripts/AddNew.cs:11)
UnityEngine.GameObject:SendMessage(String, Object, SendMessageOptions)
UIButtonMessage:Send() (at Assets/NGUI/Scripts/Interaction/UIButtonMessage.cs:77)
UIButtonMessage:OnClick() (at Assets/NGUI/Scripts/Interaction/UIButtonMessage.cs:56)
UnityEngine.GameObject:SendMessage(String, Object, SendMessageOptions)
UICamera:Notify(GameObject, String, Object) (at Assets/NGUI/Scripts/UI/UICamera.cs:644)
UICamera:ProcessTouch(Boolean, Boolean) (at Assets/NGUI/Scripts/UI/UICamera.cs:1147)
UICamera:ProcessMouse() (at Assets/NGUI/Scripts/UI/UICamera.cs:906)
UICamera:Update() (at Assets/NGUI/Scripts/UI/UICamera.cs:761)