This is a list of frequently asked questions and answers asked on the email@example.com mailing list regarding the W3C CSS Validator. Please direct questions to the mailing list, not the author of this FAQ.
org.xml.sax.SAXException: Please, fix your system identifier (URI) in the DOCTYPE rule." mean?
Your XHTML document contains a document type declaration but the system identifier points at some non-W3C URI. Your document probably contains something like this:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "DTD/xhtml1-strict.dtd">
If your document is located at e.g.
http://my.example/ this relative system identifier
would point at
http://my.example/DTD/xhtml1-strict.dtd and there
is certainly no such DTD
So you must fix the system identifier to point at some valid URI. Consider these examples for XHTML 1.0:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd">
I/O Error: Unknown mime type: some/type" mean?
Cascading Style Sheets must be declared as
text/css, see RFC 2318, "The
text/css Media Type" for details. Your server must be
configured to return this MIME type, if you don't know how to
do this, refer to your webserver's manual or your system
administrator or the support of your hosting company.
An invalid XML character (Unicode: 0x????) was found in the element content of the document." mean?
Your XHTML documents contains characters not encoded as UTF-8 or UTF-16 and misses an encoding declaration in the XML declaration. Declare your encodings like:
<?xml version='1.0' encoding='iso-8859-1'?>
prior to your document type declaration, or encode the
document with UTF-8 (e.g. by using named entities like
ö for 'ö')
Please refer to the announcement by Philippe Le Hegaret. Philippe writes: