title: What would cause this IllegalArgumentException during event dispatching?
body: <p>This is the stack trace that is generated:</p>
  
  <pre><code>Exception occurred during event dispatching:
  java.lang.IllegalArgumentException: Cannot format given Object as a Number
      at java.text.DecimalFormat.format(Unknown Source)
      at java.text.Format.format(Unknown Source)
      at javax.swing.JTable$DoubleRenderer.setValue(Unknown Source)
      at javax.swing.table.DefaultTableCellRenderer.getTableCellRendererComponent(Unknown Source)
      at javax.swing.JTable.prepareRenderer(Unknown Source)
      at javax.swing.plaf.basic.BasicTableUI.paintCell(Unknown Source)
      at javax.swing.plaf.basic.BasicTableUI.paintCells(Unknown Source)
      at javax.swing.plaf.basic.BasicTableUI.paint(Unknown Source)
      at javax.swing.plaf.ComponentUI.update(Unknown Source)
      at javax.swing.JComponent.paintComponent(Unknown Source)
      at javax.swing.JComponent.paint(Unknown Source)
      at javax.swing.JComponent.paintChildren(Unknown Source)
      at javax.swing.JComponent.paint(Unknown Source)
      at javax.swing.JViewport.paint(Unknown Source)
      at javax.swing.JComponent.paintChildren(Unknown Source)
      at javax.swing.JComponent.paint(Unknown Source)
      at javax.swing.JComponent.paintToOffscreen(Unknown Source)
      at javax.swing.BufferStrategyPaintManager.paint(Unknown Source)
      at javax.swing.RepaintManager.paint(Unknown Source)
      at javax.swing.JComponent._paintImmediately(Unknown Source)
      at javax.swing.JComponent.paintImmediately(Unknown Source)
      at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
      at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
      at javax.swing.RepaintManager.seqPaintDirtyRegions(Unknown Source)
      at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(Unknown Source)
      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.pumpEventsForFilter(Unknown Source)
      at java.awt.Dialog$1.run(Unknown Source)
      at java.awt.Dialog$3.run(Unknown Source)
      at java.security.AccessController.doPrivileged(Native Method)
      at java.awt.Dialog.show(Unknown Source)
      at java.awt.Component.show(Unknown Source)
      at java.awt.Component.setVisible(Unknown Source)
      at java.awt.Window.setVisible(Unknown Source)
      at java.awt.Dialog.setVisible(Unknown Source)
      //a call to setVisible(true)
      //some function calls that initialize the dialog box
      //However, the problem occurs AFTER the dialog box is open, when check
      //boxes are clicked on/off in certain orders. Unfortunately, I can't
      //share any of this code.
      //Currently, I'm examining the event that's fired. But other ideas are
      //welcome.
      at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
      at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
      at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
      at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
      at javax.swing.plaf.basic.BasicButtonListener.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.Window.dispatchEventImpl(Unknown Source)
      at java.awt.Component.dispatchEvent(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)
  </code></pre>
  
  <p>The weird thing is that the order I check and uncheck the JCheckBox-es matters. I'm trying to see if there's a pattern, but I don't have enough data yet. I'm just trying to get some ideas on where to go looking for potential problems.</p>
  
  <p>EDIT 1: I just checked the four methods called in the edited lines of the stack trace. They are only called when the window opens to initially populate the fields with the required data. Once the dialog is open, they are never called, so they aren't the problem.</p>
  
  <p>EDIT 2: After triple checking the state of every variable in the edited out function calls, I've pretty much eliminated them as being culprits.</p>