<?xml version="1.0"?>
<xsd:schema xmlns:xsd = "http://www.w3.org/2001/XMLSchema"
xmlns = "http://www.xyz.de"
targetNamespace= "http://www.xyz.de> <xsd:element name="bausparAntrag"><complexType>...  The Instance:<?xml version="1.0" standalone="no"?>
<bausparAntrag xmlns ="http://www.profi-consult.de"
xmlns:xsi="http://www.w3.org/2000/10/XMLSchema-instance"
xsi:schemaLocation="bausparAntrag.xsd">
<produkt> Or with this variant, the error is:Element type "bausparAntrag" must be declared.

You seem to have mixed up your namespaces. In the instance your using the namespace "http://www.profi-consult.de" but in you schema your using the namespace "http://www.xyz.de". Try changing the namespace in your instance to "http://www.xyz.de".

Cheers,
-Eddie