There is a problem with the Evaluate XPath assertion when adding it to a SOAP-based service. It is giving the Policy Manager error "Unable to load component".
API Gateway 10.1
If you click on the [Report] button and review the report, you may see a stack trace like:
Stack Trace:
java.lang.NoClassDefFoundError: org/jvnet/staxex/util/XMLStreamReaderToXMLStreamWriter$Breakpoint
at com.sun.xml.messaging.saaj.soap.impl.ElementFactory.createNamedElement(ElementFactory.java:162)
This is resolved by upgrading the Policy Manager to 10.1 CR01.