The error Java 'org.xml.sax.SAXParseException: Content is not allowed in prolog.' can in many cases arise from a corrupt xml. The XML might have a BOM.
Just use Notepad++ to remove that BOM and parsing should work again.
Notepad++ has been around since 2003 and is one the most used editors for Windows users. It is easy to use, supports many programming languages and it is free.
I have been coding since 1998 and still do today. Java, Perl, Python and most of the webstack is what I do for a living. I am also a big video game nerd.
Find me on larshaendler.com
Still working on that LinkedIn