ERROR:java.lang.Exception: java.lang.NullPointerException

I am getting the error below when trying to load the WSDL for executing a test case:

Mon Feb 07 09:03:56 EST 2011:ERROR:java.lang.Exception: java.lang.NullPointerException
java.lang.Exception: java.lang.NullPointerException
at com.eviware.soapui.impl.support.definition.support.AbstractDefinitionContext.load(AbstractDefinitionContext.java:157)
at com.eviware.soapui.impl.support.definition.support.AbstractDefinitionContext.load(AbstractDefinitionContext.java:115)
at com.eviware.soapui.impl.support.definition.support.AbstractDefinitionContext.loadIfNecessary(AbstractDefinitionContext.java:91)
at com.eviware.soapui.impl.wsdl.actions.support.ShowDesktopPanelAction.perform(ShowDesktopPanelAction.java:44)
at com.eviware.soapui.support.action.swing.SwingActionDelegate.actionPerformed(SwingActionDelegate.java:89)
at com.eviware.soapui.support.action.swing.DefaultActionList.performDefaultAction(DefaultActionList.java:107)
at com.eviware.soapui.ui.Navigator$TreeMouseListener$1.run(Navigator.java:408)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: java.lang.NullPointerException
at com.ibm.wsdl.xml.WSDLReaderImpl.readWSDL(Unknown Source)
at com.eviware.soapui.impl.wsdl.support.wsdl.WsdlInterfaceDefinition.load(WsdlInterfaceDefinition.java:48)
at com.eviware.soapui.impl.wsdl.support.wsdl.WsdlContext.loadDefinition(WsdlContext.java:66)
at com.eviware.soapui.impl.wsdl.support.wsdl.WsdlContext.loadDefinition(WsdlContext.java:30)
at com.eviware.soapui.impl.support.definition.support.AbstractDefinitionContext.cacheDefinition(AbstractDefinitionContext.java:264)
at com.eviware.soapui.impl.support.definition.support.AbstractDefinitionContext.access$400(AbstractDefinitionContext.java:44)
at com.eviware.soapui.impl.support.definition.support.AbstractDefinitionContext$Loader.construct(AbstractDefinitionContext.java:230)
at com.eviware.soapui.support.swing.SwingWorkerDelegator.construct(SwingWorkerDelegator.java:46)
at com.eviware.soapui.support.swing.SwingWorker$2.run(SwingWorker.java:140)
at java.lang.Thread.run(Unknown Source)


I am not sure why this is happening. If I change the endpoint to a url that has the same code base, it works fine. any ideas?