java.lang.NullPointerException: Cannot get property 'stages' on null object
	at org.codehaus.groovy.runtime.NullObject.getProperty(NullObject.java:60)
	at org.codehaus.groovy.runtime.InvokerHelper.getProperty(InvokerHelper.java:172)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callGroovyObjectGetProperty(AbstractCallSite.java:302)
	at org.jenkinsci.plugins.pipeline.modeldefinition.Utils.attachExecutionModel(Utils.groovy:202)
	at org.jenkinsci.plugins.pipeline.modeldefinition.Utils$attachExecutionModel$4.call(Unknown Source)
	at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
	at com.cloudbees.groovy.cps.sandbox.DefaultInvoker.methodCall(DefaultInvoker.java:16)
	at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.call(jar:file:/var/jenkins_home/plugins/pipeline-model-definition/WEB-INF/lib/pipeline-model-definition.jar!/org/jenkinsci/plugins/pipeline/modeldefinition/ModelInterpreter.groovy:51)
	at WorkflowScript.run(WorkflowScript:7)
	at ___cps.transform___(Native Method)
	at com.cloudbees.groovy.cps.impl.ContinuationGroup.methodCall(ContinuationGroup.java:48)
	at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.dispatchOrArg(FunctionCallBlock.java:109)
	at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.fixArg(FunctionCallBlock.java:82)
	at sun.reflect.GeneratedMethodAccessor347.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.cloudbees.groovy.cps.impl.ContinuationPtr$ContinuationImpl.receive(ContinuationPtr.java:72)
	at com.cloudbees.groovy.cps.impl.PropertyishBlock$ContinuationImpl.get(PropertyishBlock.java:76)
	at com.cloudbees.groovy.cps.LValueBlock$GetAdapter.receive(LValueBlock.java:30)
	at com.cloudbees.groovy.cps.impl.PropertyishBlock$ContinuationImpl.fixName(PropertyishBlock.java:66)
	at sun.reflect.GeneratedMethodAccessor349.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.cloudbees.groovy.cps.impl.ContinuationPtr$ContinuationImpl.receive(ContinuationPtr.java:72)
	at com.cloudbees.groovy.cps.impl.ConstantBlock.eval(ConstantBlock.java:21)
	at com.cloudbees.groovy.cps.Next.step(Next.java:58)
	at com.cloudbees.groovy.cps.Continuable.run0(Continuable.java:154)
	at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.access$001(SandboxContinuable.java:18)
	at org.jenkinsci.plugins.workflow.cps.SandboxContinuable$1.call(SandboxContinuable.java:33)
	at org.jenkinsci.plugins.workflow.cps.SandboxContinuable$1.call(SandboxContinuable.java:30)
	at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.GroovySandbox.runInSandbox(GroovySandbox.java:108)
	at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.run0(SandboxContinuable.java:30)
	at org.jenkinsci.plugins.workflow.cps.CpsThread.runNextChunk(CpsThread.java:163)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:324)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$100(CpsThreadGroup.java:78)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:236)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:224)
	at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:63)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:112)
	at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)