Getting HessianProtocolException: unknown code:C #2046

I am attempting to automate QuickBuild configuration changes using the com.pmease.quickbuild Java API. We are now running QuickBuild version 4.0.61. The only Java automation we have written in the past was for QuickBuild 1. I am using class com.pmease.quickbuild.RemoteService, method getConfigurationByHierarchyName to obtain a configuration from our new QuickBuild 4 instance. When I ran the program, I get a HessianProtocolException. Line 40 of the following code snippet throws the exception:


     34
     35         RemoteService remote = (RemoteService) factory.create(RemoteService.class, url);
     36
     37         // get the configuration to be copied
     38
     39         try {
     40            ConfigurationFacade configurationToCopy = remote.getConfigurationByHierarchyName(config);
     41            if (configurationToCopy == null)
     42                throw new RuntimeException("Cannot find configuration" + config);
     43         } catch (Exception e) {
     44                  System.out.println("Can't get configuration: " + config + "  from url: " + url + "\n" );
     45                  e.printStackTrace();
     46                  System.exit(1);
     47         }

Here is the error message and stacktrace I see when I run the program:

Can't get configuration: root.appname from url: http://ourhostname.dev.orgname.org:8810 ... ce=hessian

com.caucho.hessian.io.HessianProtocolException: unknown code:C
at com.caucho.hessian.io.HessianInput.error(HessianInput.java:1633)
at com.caucho.hessian.io.HessianInput.readObject(HessianInput.java:1137)
at com.caucho.hessian.io.JavaDeserializer.readMap(JavaDeserializer.java:123)
at com.caucho.hessian.io.JavaDeserializer.readMap(JavaDeserializer.java:105)
at com.caucho.hessian.io.AbstractMapDeserializer.readObject(AbstractMapDeserializer.java:75)
at com.caucho.hessian.io.HessianInput.readObject(HessianInput.java:1038)
at com.caucho.hessian.io.HessianInput.readReply(HessianInput.java:279)
at com.caucho.hessian.client.HessianProxy.invoke(HessianProxy.java:181)
at $Proxy0.getConfigurationByHierarchyName(Unknown Source)
at qbUtils.GetConfigurationId.main(GetConfigurationId.java:40)

Any ideas why this isn't working?

thanks much for your assistance!