Creator map for class MongoDB.Bson.IO.BsonDocumentWriter has 2 arguments, but none are configured. help

Working with Data Drivers
1

hi.
i’m trying to create a a document from a class created runtime.

let me show what i have

this is my classes

[BsonDiscriminator("File")]
[BsonIgnoreExtraElements]
public class BsonFile
{
    [BsonElement]
    public BsonEntry[] _entries;
}


[BsonDiscriminator("Entry")]
[BsonIgnoreExtraElements]
public class BsonEntry
{
    [BsonId]
    public string _classID {get; set;}
    [BsonDictionaryOptions(DictionaryRepresentation.Document)]
    public Dictionary<string,BsonArray> _dictionary {get; set;}
}

and this is what i do

    BsonFile file = 
    new BsonFile();
    
    file._entries =
        _propDic.Values.ToArray();
    
    writer.WriteStartDocument();
    var entry = file.ToBsonDocument();
    var bson =  BsonDocument.Create(entry);
    doc.Add(bson);
    writer.WriteEndDocument();

where _propDic is contains the array of BsonEntry that will be stored in the BsonFile class.

what i’m doing wrong?