This error normally occurs if the DocumentBuilderFactory is overlapped by e.g. gnujaxp or an outdated Xerces version.
Solution: Try to point to Xerces, e.g. by using a system var or remove suspicious jars, e.g. gnujaxp.jar from your classpath.
(Asked by a colleague today).
A better error message would be useful, must check how the behaviour is in Axis2.