Try the following:
- Check if there is a line with your user really exists in standalone/configuration/application-users.properties
- Create the file jboss-ejb-client.properties in your classpath root with the following content:
remote.connectionprovider.create.options.org.xnio.Options.SSL_ENABLED=false
remote.connections=default
remote.connection.default.host=localhost
remote.connection.default.port = 4447
remote.connection.default.connect.options.org.xnio.Options.SASL_POLICY_NOANONYMOUS=false