Crimson SAXParseException - Undeclared prefix: "xsi:noNamespaceSchemaLocation".

I'm working with a really old XML parser (Crimson v?).  I'm getting the following stacktrace (shortened to the relevant top part) trying to parse an xml file with the schema present in the same directory.  I've searched and can not find a solution that doesn't involve changing parsers.  Is this possible?

org.xml.sax.SAXParseException: Undeclared prefix: "xsi:noNamespaceSchemaLocation". 
     at org.apache.crimson.parser.Parser2.error(Parser2.java:3013) 
     at org.apache.crimson.parser.Parser2.processName(Parser2.java:1581) 
     at org.apache.crimson.parser.Parser2.processAttributeNS(Parser2.java:1553) 
     at org.apache.crimson.parser.Parser2.maybeElement(Parser2.java:1410) 
     at org.apache.crimson.parser.Parser2.parseInternal(Parser2.java:499) 
     at org.apache.crimson.parser.Parser2.parse(Parser2.java:304) 
     at org.apache.crimson.parser.XMLReaderImpl.parse(XMLReaderImpl.java:433) 
     at org.apache.commons.digester.Digester.parse(Digester.java:1631)

Thanks,
Jon