After getting onNext for AuthResult<Account> in CombinedServicesClient I get onError with below exception

gistfile1.txt

private CombinedServicesClient accountRestClient;

accountRestClient.getPermissions(args.account().id()).subscribe(
			new Observer<Permissions>() {


Activate on com.barchart.plugin.widget.sandbox.client.BackendClientTest@52339045
Account ==== 0d3c5b7b-5360-49bd-bf28-13d08c31562c
java.lang.Exception: Signatures do not match
	at com.barchart.rest.client.RestClientBase$ResponseTransformer.call(RestClientBase.java:308)
	at com.barchart.rest.client.RestClientBase$ResponseTransformer.call(RestClientBase.java:294)
	at rx.operators.OperationMap$1.call(OperationMap.java:51)
	at rx.operators.OperationMap$1.call(OperationMap.java:48)
	at rx.operators.OperationMap$MapObservable$1.onNext(OperationMap.java:124)
	at rx.operators.SafeObserver.onNext(SafeObserver.java:121)
	at rx.operators.OperationMap$MapObservable$1.onNext(OperationMap.java:124)
	at rx.operators.SafeObserver.onNext(SafeObserver.java:121)
	at com.barchart.rest.client.transport.URLConnectionTransport$2.run(URLConnectionTransport.java:163)
	at com.barchart.rest.client.transport.URLConnectionTransport$1.onSubscribe(URLConnectionTransport.java:54)
	at rx.Observable.subscribe(Observable.java:212)
	at rx.operators.OperationMap$MapObservable.onSubscribe(OperationMap.java:121)
	at rx.operators.OperationMap$2.onSubscribe(OperationMap.java:75)
	at rx.Observable.subscribe(Observable.java:212)
	at rx.operators.OperationMap$MapObservable.onSubscribe(OperationMap.java:121)
	at rx.operators.OperationMap$2.onSubscribe(OperationMap.java:75)
	at rx.Observable.subscribe(Observable.java:212)
	at rx.operators.OperationMerge$MergeObservable.onSubscribe(OperationMerge.java:132)
	at rx.operators.OperationMerge$1.onSubscribe(OperationMerge.java:52)
	at rx.Observable.subscribe(Observable.java:222)
	at com.barchart.plugin.widget.sandbox.client.BackendClientTest.onNext(BackendClientTest.java:55)
	at com.barchart.plugin.widget.sandbox.client.BackendClientTest.onNext(BackendClientTest.java:1)
	at rx.operators.SafeObserver.onNext(SafeObserver.java:121)
	at rx.operators.OperationMap$MapObservable$1.onNext(OperationMap.java:124)
	at rx.operators.SafeObserver.onNext(SafeObserver.java:121)
	at rx.subjects.ReplaySubject$SubscriptionFunc.call(ReplaySubject.java:97)
	at rx.subjects.ReplaySubject$SubscriptionFunc.call(ReplaySubject.java:88)
	at rx.subjects.ReplaySubject$DelegateSubscriptionFunc.onSubscribe(ReplaySubject.java:84)
	at rx.Observable.subscribe(Observable.java:212)
	at rx.operators.OperationCache$1.onSubscribe(OperationCache.java:59)
	at rx.Observable.subscribe(Observable.java:212)
	at rx.operators.OperationMap$MapObservable.onSubscribe(OperationMap.java:121)
	at rx.operators.OperationMap$2.onSubscribe(OperationMap.java:75)
	at rx.Observable.subscribe(Observable.java:222)
	at com.barchart.plugin.widget.sandbox.client.BackendClientTest.activate(BackendClientTest.java:35)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.apache.felix.scr.impl.helper.BaseMethod.invokeMethod(BaseMethod.java:227)
	at org.apache.felix.scr.impl.helper.BaseMethod.access$500(BaseMethod.java:38)
	at org.apache.felix.scr.impl.helper.BaseMethod$Resolved.invoke(BaseMethod.java:591)
	at org.apache.felix.scr.impl.helper.BaseMethod.invoke(BaseMethod.java:472)
	at org.apache.felix.scr.impl.helper.ActivateMethod.invoke(ActivateMethod.java:146)
	at org.apache.felix.scr.impl.manager.ImmediateComponentManager.createImplementationObject(ImmediateComponentManager.java:226)
	at org.apache.felix.scr.impl.manager.ImmediateComponentManager.createComponent(ImmediateComponentManager.java:118)
	at org.apache.felix.scr.impl.manager.AbstractComponentManager$Unsatisfied.activate(AbstractComponentManager.java:997)
	at org.apache.felix.scr.impl.manager.AbstractComponentManager.activateInternal(AbstractComponentManager.java:333)
	at org.apache.felix.scr.impl.manager.AbstractComponentManager.enable(AbstractComponentManager.java:157)
	at org.apache.felix.scr.impl.config.ConfiguredComponentHolder.enableComponents(ConfiguredComponentHolder.java:256)
	at org.apache.felix.scr.impl.BundleComponentActivator.loadDescriptor(BundleComponentActivator.java:253)
	at org.apache.felix.scr.impl.BundleComponentActivator.initialize(BundleComponentActivator.java:147)
	at org.apache.felix.scr.impl.BundleComponentActivator.<init>(BundleComponentActivator.java:111)
	at org.apache.felix.scr.impl.Activator.loadComponents(Activator.java:285)
	at org.apache.felix.scr.impl.Activator.bundleChanged(Activator.java:203)
	at org.apache.felix.framework.util.EventDispatcher$3.run(EventDispatcher.java:861)
	at java.security.AccessController.doPrivileged(Native Method)
	at org.apache.felix.framework.util.EventDispatcher.invokeBundleListenerCallback(EventDispatcher.java:858)
	at org.apache.felix.framework.util.EventDispatcher.fireEventImmediately(EventDispatcher.java:789)
	at org.apache.felix.framework.util.EventDispatcher.fireBundleEvent(EventDispatcher.java:514)
	at org.apache.felix.framework.Felix.fireBundleEvent(Felix.java:4244)
	at org.apache.felix.framework.Felix.startBundle(Felix.java:1923)
	at org.apache.felix.framework.Felix.setActiveStartLevel(Felix.java:1191)
	at org.apache.felix.framework.FrameworkStartLevelImpl.run(FrameworkStartLevelImpl.java:295)
	at java.lang.Thread.run(Unknown Source)

I am facing the same error.