When running the SelfRegistration XML sample, the response code of 500 and the resulting SOAP response comes back with a "Not authorized for service" fault code.
Identity Manager 14.x
Since the self registration task is a public task, check that the URL for the TEWS post contains the public alias for your Identity Manager environment instead of the private alias.
So the SOAP request should go to: http://<MachineName>:9080/idm/TEWS6/publicalias/ and NOT: http://<MachineName>:9080/idm/TEWS6/privatealias/.
If the sample settings.properties file located under the /tools/samples/webservices/XML folder is being used, the environment name should be set to the private alias.