If you're seeing the following error in the IBM Social Business Toolkit SDK:
Error received. Error Code = 500. Error Message = Error 500: java.lang.LinkageError: loading constraint violation: loader "org/eclipse/osgi/internal/baseadaptor/DefaultClassLoader@22d0cf8" previously initiated loading for a different type with name "org/apache/http/client/methods/HttpUriRequest" defined by loader "com/ibm/ws/classloader/CompoundClassLoader@7baea5"
Try changing the classloader of the EAR and modules to PARENT_LAST. I'm using Rational Application Developer to launch a local WebSphere 8 application server, which is how I came to encounter the above LinkageError. To resolve right mouse-click the com.ibm.sbt.sample.ear project and select Java EE -> Open WebSphere Application Server Deployment. You can then set the classloader mode to PARENT_LAST on the resulting editor's Application section. Additional context or alternative solutions are welcomed as comments.