Weird Java exception XML parsing

For the last couple of weeks, I've been unable to start any of our Java-based Thrift services that require XML configuration on my development workstation. They've been dying with the following informative exception:


[java] Caused by: java.lang.UnsupportedOperationException: This parser does not support specification "null" version "null"
[java] at javax.xml.parsers.DocumentBuilderFactory.setSchema(DocumentBuilderFactory.java:489)
[java] at com.amiestreet.service.facebook.FacebookConfig.createDocumentBuilder(FacebookConfig.java:82)


The same code from the same tree and the same classpath works fine on our VM development systems and our production servers.

After a bit of a witch-hunt, with innocent bystanders such as OpenOffice.org killed along the way, I finally traced the problem to a file /usr/lib/jvm/java-1.5.0-sun/jre/lib/ext/xerces.jar. No idea how it got there, but figured I'd contribute to the google results for this problem and save some poor soul some aggravation down the road.