Getting error related to groovy scripting

Hi,

I am trying to retrieve the JSON response from rest API to change the value of the particular node using groovy in soapui free version.

Code:
import com.eviware.soapui.support.XmlHolder

def groovyUtils = new com.eviware.soapui.support.GroovyUtils(context)
def response = context.expand( '${GETREQ#Response}' )
def holder = groovyUtils.getXmlHolder( response )

Error

But i am getting below error :

Fri Jun 15 12:38:58 IST 2018:ERROR:org.apache.xmlbeans.XmlException: error: Unexpected element: CDATA
org.apache.xmlbeans.XmlException: error: Unexpected element: CDATA
at org.apache.xmlbeans.impl.store.Locale$SaxLoader.load(Locale.java:3486)
at org.apache.xmlbeans.impl.store.Locale.parse(Locale.java:712)
at org.apache.xmlbeans.impl.store.Locale.parseToXmlObject(Locale.java:696)
at org.apache.xmlbeans.impl.store.Locale.parseToXmlObject(Locale.java:683)
at org.apache.xmlbeans.impl.schema.SchemaTypeLoaderBase.parse(SchemaTypeLoaderBase.java:208)
at org.apache.xmlbeans.XmlObject$Factory.parse(XmlObject.java:580)
at com.eviware.soapui.support.xml.XmlUtils.createXmlObject(XmlUtils.java:215)
at com.eviware.soapui.support.XmlHolder.<init>(XmlHolder.java:39)
at com.eviware.soapui.support.XmlHolder.<init>(XmlHolder.java:52)
at com.eviware.soapui.support.GroovyUtils.getXmlHolder(GroovyUtils.java:67)
at com.eviware.soapui.support.GroovyUtils$getXmlHolder.call(Unknown Source)
at Script38.run(Script38.groovy:13)
at com.eviware.soapui.support.scripting.groovy.SoapUIGroovyScriptEngine.run(SoapUIGroovyScriptEngine.java:90)
at com.eviware.soapui.impl.wsdl.teststeps.WsdlGroovyScriptTestStep.run(WsdlGroovyScriptTestStep.java:141)
at com.eviware.soapui.impl.wsdl.panels.teststeps.GroovyScriptStepDesktopPanel$RunAction$1.run(GroovyScriptStepDesktopPanel.java:250)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: org.xml.sax.SAXParseException; systemId: file:; lineNumber: 1; columnNumber: 1; Unexpected element: CDATA
at org.apache.xmlbeans.impl.piccolo.xml.Piccolo.reportFatalError(Piccolo.java:1038)
at org.apache.xmlbeans.impl.piccolo.xml.Piccolo.parse(Piccolo.java:723)
at org.apache.xmlbeans.impl.store.Locale$SaxLoader.load(Locale.java:3454)
... 17 more

Please help me to resolve this issue