I'm trying to implement the IXmlSerialization for class SerializableDictionary. When starts the serialization of class to xml, I'm catching the System.NotSupportedException: 'Can't flush final block twice'. The problem occurs when second serializer trying to call Serialize method on same XmlWriter. 

using (var archive = new ZipArchive(stream, ZipArchiveMode.Create, false, null))
    {
        foreach (var item in array)
        {
            using (var entry = archive.CreateEntry($"{item.Name}.reg-ext"))
            {
                XmlInOut<RegulationItem>.SaveToStream(entry.Open(), item);
            }
        }
    }

Could it be bug with the ArchiveEntry Stream?

I've placed a solution into a github repo. Also I tried to replace the stream of entry with the MemoryStream, and it helps. But I would to do it directly, if it's possible. 

The original question.