A public property with a private setter will throw. E.g::

public IList<EventSession> Sessions

{ get; private set; }

Error is occurring inBsonPropertyMapper.cs line 226 because call to propertyInfo.GetSetmethod() is throwing.

public override Action<object, object> Setter {
get {
if (setter == null)

{ var setMethodInfo = propertyInfo.GetSetMethod(); // This throws var setMethodDelegate = (Action<TClass, TProperty>) Delegate.CreateDelegate(typeof(Action<TClass, TProperty>), setMethodInfo); setter = (obj, value) => setMethodDelegate((TClass) obj, (TProperty) value); }

return setter;
}
}