Caused by: java.lang.NoSuchMethodError: org.apache.commons.codec.binary.Base64.encodeBase64String([B)Ljava/lang/String;
at org.jbpm.integration.console.shared.GuvnorConnectionUtils.applyAuth(GuvnorConnectionUtils.java:391) [jbpm-gwt-shared-5.2.0.Final.jar:]
at org.jbpm.integration.console.shared.GuvnorConnectionUtils.guvnorExists(GuvnorConnectionUtils.java:484) [jbpm-gwt-shared-5.2.0.Final.jar:]
at org.jbpm.integration.console.CommandDelegate.newStatefulKnowledgeSession(CommandDelegate.java:105) [jbpm-gwt-core-5.2.0.Final.jar:]
... 40 more
This method was added afaik in commons codec 1.4. The error looks like you have some commons codec jar version < 1.4 which gets loaded first.