Possible causes for "schema feature not recognized for SAX driver"

I am trying to execute a program developed elsewhere, and I see the following exception:

org.jdom.RuntimeExc开发者_C百科eption: http://apache.org/xml/features/validation/schema 
feature not recognized for SAX driver org.apache.cimson.parser.XMLReaderImpl

This program ran successfully a few months ago, but my development platform was rebuilt (apparently into a different configuration). Any ideas why this program is now throwing the above exception?

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This is an Xerces feature (as listed here). Thus, you need to download and put Xerces in the classpath.