With oXygen XML Editor 9.2 on Mac, I tried from the xslt debugger with Saxon 9B to have parse-gedcom.xsl work with input kennedy.ged.
Before running the debugger, I had configured a parameter input = '/Users/jacquesfauquex/Downloads/ch19/kennedy.ged'
After running the debugger, the result window shows
Description: Content is not allowed in prolog.
E Content is not allowed in prolog. - 1:0
F Content is not allowed in prolog. - 1:0
... it looks like that xslt doesn't like to parse a text document instead of a xml document. Though, to parse text document is what the example wants to demostrate...
What do I do wrong?