Common OpenSAML Errors
The following errors are commonly encountered by users.
org.opensaml.xml.XMLConfigurator: Configuration file does not validate against schema org.xml.sax.SAXParseException: UndeclaredPrefix: Cannot resolve 'xt:DEFAULT' as a QName: the prefix 'xt' is not declared.
This error is always because you did not not endorse Xerces and Xalan. If you think you did then you have made a mistake, perhaps because your application container isn't doing what you think it's doing (for example, Tomcat "helpfully" overrides the default location of the endorsed library directory).
XMLObjectBuilder is null
If you attempt to get an XMLObjectBuilder for a given schema type or element name and it is null this is usually caused by one of two things. You didn't load the configuration files into OpenSAML (e.g. by means of the DefaultBootstrap) or their is a typo in either your configuration file or code. The schema URI is the most common location for this kind of typo.