Are you using this locally or on a server? For local file paths you need file://. If you are on a server you should be able to load it with something like /HOMEPAGE/xampp/htdocs/saschak/photo/alben/original/info.xml. I'm use to linux web servers which you use /home/userName/theFolder/theFile.xml

Try this:

fo.addVariable("xmlDataPath", "file://S:/HOMEPAGE/xampp/htdocs/saschak/photo/alben/original/info.xml");