System.NullReferenceException: Object reference not set to an instance of an object. at Microsoft.SharePoint.SPContentType.ProvisionFieldOnList(SPField field, Boolean bRecurAllowed) at Microsoft.SharePoint.SPContentType.ProvisionFieldsOnList() at Microsoft.SharePoint.SPContentType.DeriveContentType(SPContentTypeCollection cts, SPContentType& ctNew) at Microsoft.SharePoint.SPContentTypeCollection.AddContentTypeToList(SPContentType contentType) at Microsoft.SharePoint.SPContentTypeCollection.AddContentType(SPContentType contentType, Boolean updateResourceFileProperty, Boolean checkName, Boolean setNextChildByte) at Microsoft.SharePoint.SPContentTypeCollection.Add(SPContentType contentType) at Microsoft.SharePoint.ApplicationPages.AddContentTypeToListPage.Update(Obj... 31fca84e-90db-435f-8de3-e4415e3f6758