System.NullReferenceException: Object reference not set to an instance of an object. at Dynamicweb.eCommerce.Indexing.ProductIndexSchemaExtender.GetFields() at Dynamicweb.Indexing.Schemas.ExtensionFieldDefinition.GetFields() at Dynamicweb.Indexing.IndexHelper.ConvertToIndex(XElement obj) at Dynamicweb.Indexing.IndexService.LoadIndex(String filename) at Dynamicweb.Indexing.Queries.IndexQueryProvider.Query(IQuery query, QuerySettings settings) at Dynamicweb.eCommerce.Frontend.Frontend.GetProductsFromIndexQuery()