An error occurred while attaching module (Dynamicweb.Frontend.Content)

System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
   at Dynamicweb.Ecommerce.FieldTypeProviders.ConversionUnitFieldTypeProviderBase.GetLanguageUnits(Dictionary`2 settings)
   at Dynamicweb.Ecommerce.FieldTypeProviders.ConversionUnitFieldTypeProviderBase.GetValue(Object value, String languageId, Dictionary`2 settings)
   at Dynamicweb.Ecommerce.Products.ProductFieldTypeProvider.GetProductValue(Product product, FieldType fieldType, Object fieldValue)
   at Dynamicweb.Ecommerce.Products.ProductFieldValueCollection.RefreshProviderFields(Product product)
   at Dynamicweb.Ecommerce.Products.ProductRepository.ExtractProduct(IDataReader dataReader, Nullable`1& groupProductRelationSortingExists)
   at Dynamicweb.Ecommerce.Products.ProductRepository.GetProductsBySql(CommandBuilder query, Boolean doRefactoring, Boolean bulkFill, Boolean useAssortments)
   at Dynamicweb.Ecommerce.Products.ProductRepository.GetProductsByAutoIDs(Int64[] autoIDs, Boolean excludeHiddenProducts)
   at Dynamicweb.Ecommerce.Products.ProductRepository.BulkGetProductsByAutoIDs(Int64[] autoIDs)
   at Dynamicweb.Ecommerce.Products.ProductService.FetchByAutoIDsInternal(IProductRepository repo, IEnumerable`1 keys)
   at Dynamicweb.Caching.ServiceCache`2.GetAlternativeCache[T](String name, IEnumerable`1 keys)
   at Dynamicweb.Ecommerce.Products.ProductService.GetByAutoIDs(IList`1 autoIDs)
   at Dynamicweb.Ecommerce.ProductCatalog.ViewModelFactory.CreateView(ProductListViewModelSettings settings, IEnumerable`1 productAutoIds)
   at Dynamicweb.Ecommerce.ProductCatalog.ProductCatalogFrontend.RenderProductList(ProductCatalogSettings settings, QuerySettings querySettings, IQuery query, String groupId, Boolean feed)
   at Dynamicweb.Ecommerce.ProductCatalog.ProductCatalogFrontend.GetContent()
   at Dynamicweb.Frontend.Content.GetModuleOutput(Paragraph paragraph, PageView pageview)