Convert XSD schema to C# classes. Serialize/Deserialize IFC to Objects

When I cconvert IFC4 XSD schema downloaded from BuildingSmart web page and I traduce to C# classes using xsd.exe with the terminal, we find an error with XmlQualifiedName due to a itemtype named QName inside de schema. If I change this itemtype to “string”, the traduction is finished correctly.
Is this an error inside the shema? How can I create/update my C# classes for each new version launched?
I am using IFCXML to serialize/deserialize IFC to Objects through this classes (in this case C# objects). Ís there any other way to do this conversion? I investigate IFC2JSON and others but in these cases we have the serialize way but to deserilize we need to map class by class all IFC schema (not a good solution i think).

Obviously, I also use XBIM and IFCOpenShell but in this cases I only want a support to traduce for each version IFC files to Objects without use external frameworks.