ERROR
ERROR(RSC-005): my-file.epub/OEBPS/toc.ncx(14,32): Error while parsing file 'value of attribute "id" is invalid; must be an XML name without colons'.
Solution
verify the content source path of files declared on toc.ncx
change the attribute inside id (if only number) to "navpoint-x"
verify document type
if have
<!DOCTYPE ncx PUBLIC "-//NISO//DTD ncx 2005-1//EN" "http://www.daisy.org/z3986/2005/ncx-2005-1.dtd"><ncx version="2005-1" xml:lang="en" xmlns="http://www.daisy.org/z3986/2005/ncx/">
change to
<!DOCTYPE ncx PUBLIC "-//NISO//DTD ncx 2005-1//EN" "http://www.daisy.org/z3986/2005/ncx-2005-1.dtd"><ncx version="2005-1" xmlns="http://www.daisy.org/z3986/2005/ncx/">
change the attribute inside id (if only number) to "navpoint-x"
verify document type
if have
<!DOCTYPE ncx PUBLIC "-//NISO//DTD ncx 2005-1//EN" "http://www.daisy.org/z3986/2005/ncx-2005-1.dtd"><ncx version="2005-1" xml:lang="en" xmlns="http://www.daisy.org/z3986/2005/ncx/">
change to
<!DOCTYPE ncx PUBLIC "-//NISO//DTD ncx 2005-1//EN" "http://www.daisy.org/z3986/2005/ncx-2005-1.dtd"><ncx version="2005-1" xmlns="http://www.daisy.org/z3986/2005/ncx/">
