Server side error in DnD

2013-05-24 18:04:41,157 ERROR [org.nuxeo.ecm.webengine.app.WebEngineExceptionMapper] Exception in JAX-RS processing
java.lang.NullPointerException
        at java.util.ArrayList.<init>(ArrayList.java:151)
        at org.nuxeo.ecm.automation.core.util.BlobList.<init>(BlobList.java:34)
        at org.nuxeo.ecm.automation.server.jaxrs.batch.BatchResource.exec(BatchResource.java:108)
        at sun.reflect.GeneratedMethodAccessor8485.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:601)
        at com.sun.jersey.spi.container.JavaMethodInvokerFactory$1.invoke(JavaMethodInvokerFactory.java:60)
        at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ObjectOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:258)
        at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
        at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
        at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)