java.lang.NullPointerException
  at org.ohdsi.rabbitInAHat.dataModel.ItemToItemMap.hashCode(ItemToItemMap.java:66)
  at java.util.HashMap.hash(HashMap.java:351)
  at java.util.HashMap.putForCreate(HashMap.java:512)
  at java.util.HashMap.readObject(HashMap.java:1156)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:606)
  at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1017)
  at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1891)
  at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1796)
  at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)
  at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1989)
  at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1913)
  at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1796)
  at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)
  at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)
  at org.ohdsi.rabbitInAHat.dataModel.ETL.fromFile(ETL.java:148)
  at org.ohdsi.rabbitInAHat.RabbitInAHatMain.doOpenSpecs(RabbitInAHatMain.java:389)
  at org.ohdsi.rabbitInAHat.RabbitInAHatMain.<init>(RabbitInAHatMain.java:131)
  at org.ohdsi.rabbitInAHat.RabbitInAHatMain.main(RabbitInAHatMain.java:75)
java.lang.NullPointerException
  at org.ohdsi.rabbitInAHat.RabbitInAHatMain.doOpenSpecs(RabbitInAHatMain.java:390)
  at org.ohdsi.rabbitInAHat.RabbitInAHatMain.<init>(RabbitInAHatMain.java:131)
  at org.ohdsi.rabbitInAHat.RabbitInAHatMain.main(RabbitInAHatMain.java:75)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
  at org.ohdsi.rabbitInAHat.RabbitInAHatMain.doSetTargetCDM(RabbitInAHatMain.java:337)
  at org.ohdsi.rabbitInAHat.RabbitInAHatMain.actionPerformed(RabbitInAHatMain.java:328)
  at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
  at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
  at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
  at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
  at javax.swing.AbstractButton.doClick(AbstractButton.java:376)
  at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:833)
  at com.apple.laf.AquaMenuItemUI.doClick(AquaMenuItemUI.java:157)
  at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:877)
  at java.awt.Component.processMouseEvent(Component.java:6505)
  at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
  at java.awt.Component.processEvent(Component.java:6270)
  at java.awt.Container.processEvent(Container.java:2229)
  at java.awt.Component.dispatchEventImpl(Component.java:4861)
  at java.awt.Container.dispatchEventImpl(Container.java:2287)
  at java.awt.Component.dispatchEvent(Component.java:4687)
  at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
  at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
  at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
  at java.awt.Container.dispatchEventImpl(Container.java:2273)
  at java.awt.Window.dispatchEventImpl(Window.java:2719)
  at java.awt.Component.dispatchEvent(Component.java:4687)
  at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
  at java.awt.EventQueue.access$200(EventQueue.java:103)
  at java.awt.EventQueue$3.run(EventQueue.java:694)
  at java.awt.EventQueue$3.run(EventQueue.java:692)
  at java.security.AccessController.doPrivileged(Native Method)
  at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
  at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
  at java.awt.EventQueue$4.run(EventQueue.java:708)
  at java.awt.EventQueue$4.run(EventQueue.java:706)
  at java.security.AccessController.doPrivileged(Native Method)
  at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
  at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
  at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
  at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
  at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
  at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
  at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
  at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)