Problem is with CurrencyObject:
Currency Object ( [id] => [name] => [localizedNames:protected] => [iso_code] => [iso_code_num] => [numeric_iso_code] => [conversion_rate] => [deleted] => 0 [active] => [sign] => [symbol] => [localizedSymbols:CurrencyCore:private] => [format] => [blank] => [decimals] => [precision] => [webserviceParameters:protected] => Array ( [objectsNodeName] => currencies [fields] => Array ( [names] => Array ( [getter] => getLocalizedNames [i18n] => 1 ) [name] => Array ( [getter] => getName [modifier] => Array ( [http_method] => 6 [modifier] => setNameForWebservice ) ) [symbol] => Array ( [getter] => getLocalizedSymbols ) [iso_code] => Array ( [modifier] => Array ( [http_method] => 6 [modifier] => setIsoCodeForWebService ) ) ) ) [prefix] => [suffix] => [id_lang:protected] => [id_shop:protected] => [id_shop_list] => Array ( ) [get_shop_from_context:protected] => 1 [table:protected] => currency [identifier:protected] => id_currency [fieldsRequired:protected] => Array ( [0] => iso_code [1] => conversion_rate ) [fieldsSize:protected] => Array ( [iso_code] => 3 [numeric_iso_code] => 3 ) [fieldsValidate:protected] => Array ( [iso_code] => isLanguageIsoCode [numeric_iso_code] => isNumericIsoCode [precision] => isInt [conversion_rate] => isUnsignedFloat [deleted] => isBool [active] => isBool ) [fieldsRequiredLang:protected] => Array ( ) [fieldsSizeLang:protected] => Array ( [name] => 255 [symbol] => 255 ) [fieldsValidateLang:protected] => Array ( [name] => isGenericName ) [tables:protected] => Array ( ) [image_dir:protected] => [image_format:protected] => jpg [translator:protected] => [def:protected] => Array ( [table] => currency [primary] => id_currency [multilang] => 1 [fields] => Array ( [iso_code] => Array ( [type] => 3 [validate] => isLanguageIsoCode [required] => 1 [size] => 3 ) [numeric_iso_code] => Array ( [type] => 3 [validate] => isNumericIsoCode [size] => 3 ) [precision] => Array ( [type] => 1 [validate] => isInt ) [conversion_rate] => Array ( [type] => 4 [validate] => isUnsignedFloat [required] => 1 [shop] => 1 ) [deleted] => Array ( [type] => 2 [validate] => isBool ) [active] => Array ( [type] => 2 [validate] => isBool ) [name] => Array ( [type] => 3 [lang] => 1 [validate] => isGenericName [size] => 255 ) [symbol] => Array ( [type] => 3 [lang] => 1 [size] => 255 ) ) [classname] => Currency [associations] => Array ( [l] => Array ( [type] => 2 [field] => id_currency [foreign_field] => id_currency ) ) ) [update_fields:protected] => [force_id] => )
iso_code is null for some reason.