cannot import xml project -- disabled

I have been developing this project on one machine(XP) and QA uses it to run load test on another machine (windows server 2008)
Everything is fine until today, I could not import the project anymore. It is disabled, showing red cross on the icon.

The QA machine can open it fine, using the same xml file. They are both running 4.5.1

I tried 4.5.0 too on my machine, same problem.

Error is a xml parsing exception, I checked the line it complaints, didn't notice anything suspicous.

Any idea what is wrong? The file size is 41M, in case that might cause problem.

Following is the error

Error at line 661705, column 1567
org.apache.xmlbeans.XmlException: error: Unexpected element: OPEN_TAG
at org.apache.xmlbeans.impl.store.Locale$SaxLoader.load(Locale.java:3486)
at org.apache.xmlbeans.impl.store.Locale.parseToXmlObject(Locale.java:1276)
at org.apache.xmlbeans.impl.store.Locale.parseToXmlObject(Locale.java:1263)
at org.apache.xmlbeans.impl.schema.SchemaTypeLoaderBase.parse(SchemaTypeLoaderBase.java:345)
at com.eviware.soapui.config.SoapuiProjectDocumentConfig$Factory.parse(Unknown Source)
at com.eviware.soapui.impl.wsdl.WsdlProject.loadProject(WsdlProject.java:333)
at com.eviware.soapui.impl.wsdl.WsdlProject.<init>(WsdlProject.java:244)
at com.eviware.soapui.impl.wsdl.WsdlProjectFactory.createNew(WsdlProjectFactory.java:62)
at com.eviware.soapui.impl.wsdl.WsdlProjectFactory.createNew(WsdlProjectFactory.java:24)
at com.eviware.soapui.impl.WorkspaceImpl.reloadProject(WorkspaceImpl.java:539)
at com.eviware.soapui.impl.WorkspaceImpl.openProject(WorkspaceImpl.java:665)
at com.eviware.soapui.impl.wsdl.actions.project.OpenProjectAction.perform(OpenProjectAction.java:39)
at com.eviware.soapui.impl.wsdl.actions.project.OpenProjectAction.perform(OpenProjectAction.java:26)
at com.eviware.soapui.support.action.swing.SwingActionDelegate.actionPerformed(SwingActionDelegate.java:89)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.AbstractButton.doClick(Unknown Source)
at javax.swing.plaf.basic.BasicMenuItemUI.doClick(Unknown Source)
at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(Unknown Source)
at java.awt.AWTEventMulticaster.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: org.xml.sax.SAXParseException; systemId: file:; lineNumber: 661705; columnNumber: 1567; Unexpected element: OPEN_TAG
at org.apache.xmlbeans.impl.piccolo.xml.Piccolo.reportFatalError(Piccolo.java:1038)
at org.apache.xmlbeans.impl.piccolo.xml.Piccolo.parse(Piccolo.java:723)
at org.apache.xmlbeans.impl.store.Locale$SaxLoader.load(Locale.java:3454)
... 51 more