如何使用对象创建或初始化数组的对象

Question

public class CourseDocument
    {
        public ObjectId _id { get; set; }
        public string Name { get; set; }
       public List<StudentObject> StudentAccess { get; set; }
       public string EcosystemId { get; set; }
       public CourseDocument()
        {   
            StudentAccess = new List<StudentObject>();
        }
}
public class StudentObject
    {
        public long UserID { get; set; }
        public long CluKey { get; set; }
    }

....在我正在调用的api方法中

var query = await _db.CourseDocuments.FindAsync(w => w.EcosystemId == acc.Identifier);

此后，我得到错误消息“反序列化班级BankerCoreApi.Models.Courses.CourseDocument类的StudentAccess属性时发生错误：无法反序列化BsonType'Document'中的'List'。”