Q: Running FOP I get the following messages or something similar: "WARNING: Unknown formatting object http://www.w3.org/XSL/Format/1.0^root" and then a FATAL Error "Root element must be root, not default FO".
A: Make sure that you have specified as the namespace for fo the following string: "http://www.w3.org/1999/XSL/Format". It is analogous to the xslt namespace "http://www.w3.org/1999/XSL/Transform"