Since the beginning of this year 2017 the standard geo information and data of Northrhine Westphalia are available for free: https://www.opengeodata.nrw.de/produkte/geobasis/
Including also data from the land registry (land parcels, etc): https://www.opengeodata.nrw.de/produkte/geobasis/lika/alkis_sek/bda_oe/
I have downloaded and unzipped the data for Solingen and Aachen: bda_oe_05122000_Solingen_EPSG25832_NAS.zip bda_oe_05334000_Städteregion_Aachen_EPSG25832_NAS.zip
I use qgis 2.14 - I can select and see the XML-files when I select NAS as data type, which I want to open as vector layer..
But I do not see any content. The attribute table seems to be empty.
I have found out that it needs the "Xerces XML parsing library". But I do not know if it is part of QGIS 2.14?
The is a similar discussion:
How can I find out if the "Xerces XML parsing library" is installed and if not - how can I install it?