XML Schema Generation returns empty xsd

[jfk]

Hello,

I have created an XSD Schema in EA 11.1.1111 and when I try to generate the XSD file it only returns the following content:

<?xml version="1.0" encoding="utf-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"/>

Do you have any idea what is causing this behaviour?

I have created a second schema and the xsd generation is working as expected.

An XMI-export:
http://users.ugent.be/~jverhamm/ea/GISMO%20interface%20OASIS%20Land.xml

Thank you
Kind regards
Jan