WARNING: Skipping a non-existent field skipWhenFailed
com.thoughtworks.xstream.converters.reflection.NonExistentFieldException: No such field hudson.plugins.ws_cleanup.WsCleanup.skipWhenFailed
        at com.thoughtworks.xstream.converters.reflection.FieldDictionary.field(FieldDictionary.java:106)
        at com.thoughtworks.xstream.converters.reflection.PureJavaReflectionProvider.getFieldType(PureJavaReflectionProvider.java:152)
        at hudson.util.RobustReflectionConverter.determineType(RobustReflectionConverter.java:356)
        at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:229)
        at hudson.util.RobustReflectionConverter.unmarshal(RobustReflectionConverter.java:180)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:82)
        at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:63)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:76)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:60)
        at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.readItem(AbstractCollectionConverter.java:71)
        at hudson.util.CopyOnWriteList$ConverterImpl.unmarshal(CopyOnWriteList.java:193)
        at hudson.util.DescribableList$ConverterImpl.unmarshal(DescribableList.java:244)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:82)
        at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:63)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:76)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:60)
        at hudson.util.RobustReflectionConverter.unmarshalField(RobustReflectionConverter.java:290)
        at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:233)
        at hudson.util.RobustReflectionConverter.unmarshal(RobustReflectionConverter.java:180)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:82)
        at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:63)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:76)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:60)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:137)
        at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.unmarshal(AbstractTreeMarshallingStrategy.java:33)
        at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:926)
        at hudson.util.XStream2.unmarshal(XStream2.java:91)
        at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:912)
        at com.thoughtworks.xstream.XStream.fromXML(XStream.java:864)
        at hudson.XmlFile.read(XmlFile.java:133)
        at hudson.model.Items.load(Items.java:114)
        at jenkins.model.Jenkins$14.run(Jenkins.java:2360)
        at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:146)
        at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:259)
        at jenkins.model.Jenkins$5.runTask(Jenkins.java:800)
        at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:187)
        at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:94)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:722)