I see soapui.log in the bin folder. I'm using the bundled JRE version.
This is the only possible error it seems?
2014-08-25 11:49:41,279 ERROR [errorlog] java.lang.NullPointerException
java.lang.NullPointerException
at com.eviware.soapui.impl.rest.support.handlers.JsonMediaTypeHandler.createXmlRepresentation(JsonMediaTypeHandler.java:44)
at com.eviware.soapui.impl.wsdl.submit.transports.http.BaseHttpResponse.getContentAsXml(BaseHttpResponse.java:382)
at com.eviware.soapui.impl.wsdl.teststeps.RestTestRequestStep.propertyChange(RestTestRequestStep.java:430)
at java.beans.PropertyChangeSupport.fire(Unknown Source)
at java.beans.PropertyChangeSupport.firePropertyChange(Unknown Source)
at java.beans.PropertyChangeSupport.firePropertyChange(Unknown Source)
at com.eviware.soapui.model.support.AbstractModelItem.notifyPropertyChanged(AbstractModelItem.java:71)
at com.eviware.soapui.impl.support.AbstractHttpRequest.setResponse(AbstractHttpRequest.java:792)
at com.eviware.soapui.impl.wsdl.teststeps.RestTestRequest.setResponse(RestTestRequest.java:127)
at com.eviware.soapui.impl.wsdl.teststeps.RestTestRequestStep.run(RestTestRequestStep.java:809)
at com.eviware.soapui.impl.wsdl.support.AbstractTestCaseRunner.runTestStep(AbstractTestCaseRunner.java:213)
at com.eviware.soapui.impl.wsdl.testcase.WsdlTestCaseRunner.runCurrentTestStep(WsdlTestCaseRunner.java:47)
at com.eviware.soapui.impl.wsdl.support.AbstractTestCaseRunner.internalRun(AbstractTestCaseRunner.java:139)
at com.eviware.soapui.impl.wsdl.support.AbstractTestCaseRunner.internalRun(AbstractTestCaseRunner.java:47)
at com.eviware.soapui.impl.wsdl.support.AbstractTestRunner.run(AbstractTestRunner.java:129)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
