[ https://issues.jboss.org/browse/SRAMP-606?page=com.atlassian.jira.plugin.... ] Brett Meyer commented on SRAMP-606: ----------------------------------- [~giorgimode], here's the issue. RESTEasy was pulling in NamespacePrefixMapper from 2 different ClassLoaders: 1.) the com.sun.xml.bind EAP module and 2.) your app. #2 is transitive, included by the s-ramp-client dependency. The quick fix: {code} <dependency> <groupId>org.overlord.sramp</groupId> <artifactId>s-ramp-client</artifactId> <version>0.7.0-SNAPSHOT</version> <exclusions> <exclusion> <groupId>com.sun.xml.bind</groupId> <artifactId>jaxb-impl</artifactId> </exclusion> </exclusions> </dependency> ... <manifestEntries> <Dependencies>com.sun.xml.bind,org.jboss.resteasy.resteasy-jaxrs,org.apache.httpcomponents</Dependencies> </manifestEntries> {code} Note the addition of the com.sun.xml.bind module in the manifestEntries. After I did that, it worked perfectly. For now, I think the "fix" is going to be mentioning this caveat in our docs. Having to do platform-specific builds of s-ramp-client isn't really something I think we should spend time on, nor is it worth the maintenance. Hopefully that helps! -- This message was sent by Atlassian JIRA (v6.3.1#6329)