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

System.ArgumentNullException: Verdien kan ikke være null.
Parameternavn: key
   ved System.ThrowHelper.ThrowArgumentNullException(ExceptionArgument argument)
   ved System.Collections.Generic.Dictionary`2.FindEntry(TKey key)
   ved System.Collections.Generic.Dictionary`2.TryGetValue(TKey key, TValue& value)
   ved Dynamicweb.Ecommerce.ProductCategoryFieldRepository.FillFieldsWithTranslations(Dictionary`2 fieldCollection, CommandBuilder translationQuery, Dictionary`2 fieldOptionsPerField)
   ved Dynamicweb.Ecommerce.ProductCategoryFieldRepository.GetFields()
   ved Dynamicweb.Caching.DictionaryCache`2.InitializeCacheDictionary()
   ved System.Lazy`1.CreateValue()
   ved System.Lazy`1.LazyInitValue()
   ved Dynamicweb.Caching.DictionaryCache`2.GetCacheResult(IEnumerable`1 keys)
   ved Dynamicweb.Caching.ServiceCache`2.GetCache(IEnumerable`1 keys)
   ved Dynamicweb.Caching.ServiceCache`2.GetCache(TKey key)
   ved Dynamicweb.Ecommerce.ProductCategoryFieldService.GetFieldById(String categoryId, String fieldId)
   ved Dynamicweb.Ecommerce.Products.ProductField.get_CachedCategoryFields()
   ved Dynamicweb.Ecommerce.Products.ProductField.GetCategoryFields()
   ved Dynamicweb.Ecommerce.Products.ProductField.GetAllEditableProductFields()
   ved Dynamicweb.Ecommerce.Products.FieldDisplayGroups.FieldDisplayGroupService.GetDisplayGroupsFields()
   ved System.Lazy`1.CreateValue()
   ved System.Lazy`1.LazyInitValue()
   ved Dynamicweb.Ecommerce.Frontend.Renderer.RenderFieldDisplayGroups(Product product, PriceInfo productPrice, Template fieldDisplayGroupsTemplate, RenderingContext renderingContext)
   ved Dynamicweb.Ecommerce.Frontend.Renderer.RenderProduct(Product product, Boolean extendedProperties, Template template, Int32 loopCounter, Boolean renderRelated, String productUrl, Int32 quantity, Int32 wishListId, Boolean renderPublicList, Boolean isRecursiveCall, Lazy`1 categoryFieldSorting, Int32 orderLineOfProductCount, RenderingContext renderingContext, String unitId)
   ved Dynamicweb.Ecommerce.Frontend.Renderer.RenderProducts(ProductCollection products, Template parentTemplate, String loopName, Int32 loopCounter, Boolean renderRelatedProducts, Boolean renderRelatedLists, Boolean isRecursive, RenderingContext renderingContext)
   ved Dynamicweb.Ecommerce.Frontend.Renderer.RenderProductRelatedGroups(RenderingContext renderingContext, Product product, Template parentTemplate, String loopName)
   ved Dynamicweb.Ecommerce.Frontend.Renderer.RenderProduct(Product product, Boolean extendedProperties, Template template, Int32 loopCounter, Boolean renderRelated, String productUrl, Int32 quantity, Int32 wishListId, Boolean renderPublicList, Boolean isRecursiveCall, Lazy`1 categoryFieldSorting, Int32 orderLineOfProductCount, RenderingContext renderingContext, String unitId)
   ved Dynamicweb.Ecommerce.Frontend.Renderer.RenderProduct(Product product, Boolean extendedProperties, String unitId)
   ved Dynamicweb.Ecommerce.Frontend.Frontend.EcomRender()
   ved Dynamicweb.Ecommerce.Frontend.Frontend.GetContent()
   ved Dynamicweb.Frontend.Content.GetModuleOutput(Paragraph paragraph, PageView pageview)