I get warning: mb_convert_encoding() expects parameter 1 to be string, array given. But according to php.net mb_convert_encoding() accepts array. See https://www.php.net/manual/en/function.mb-convert-encoding.php mb_convert_encoding ( mixed $val , string $to_encoding [, mixed $from_encoding = mb_internal_encoding() ] ) : mixed Converts the character encoding of val to to_encoding from optionally from_encoding. If val is an array, all its string values will be converted