It seems that when using the Remoting API, some of the items returned in the ConfigurationFacade are of type HashMap, rather than the actual Facade they should be. Specifically, the "repositories" and "variables" property are returning
List<HashMap> rather than List<RepositoryFacade> and List<VariableFacade> as they should be. As a result, when I modify the configuration, and send it back to quickbuild, it complains that i'm passing invalid classes:

com.caucho.hession.io.HessianServiceException: java.lang.RuntimeException(Invalid facade class: java.util.HashMap).