I followed this threat here also, but trying to learn how to import an XML data set using the Custom XSL file "XML-Tree" you previously mentioned. I cannot find this "XML-Tree" custom XSL file - where is it?
See How to visualize my xml data?
Third, although yEd asks for a custom XSLT stylesheet when using the "XML+XSL" import, it does provide a couple of predefined stylesheets as well. These predefined stylesheets are available through the "XSL File for" drop down list.
XML-Tree is one of the predefined stylesheets.