This is related to drag select and deleting two tables connected by relationship

To make phantom tables and relationships follow

1. Create two tables within a sheet.
2. Create a relationship between the two tables.
3. Select the two tables and their relationship by dragging a selection box around them with the cursor.
4. Right click on the selected entities and delete.
5. The objects are deleted in the Model Browser, but not on the sheet.
6. Relationships can be made in the sheet between the ghost tables and tables that did not get deleted.
7. The Relationship properties indicates relationships incorrectly. It displays relationships between tables that exist only in the model browser.

Once a relationship between a phantom table and a table that exists in the model browser has been created...

1. Make a new sheet.
2. Right click in the model browser on the relationship node.
3. This node cannot be viewed, even though it is grayed out.

java.lang.NullPointerException
    at nmfl.aPP.<init>(Unknown Source)
    at nmfl.sp.<init>(Unknown Source)
    at nmfl.nA.<init>(Unknown Source)
    at nmfl.Ih.<init>(Unknown Source)
    at nmfl.avc.c(Unknown Source)
    at nmfl.asE.a(Unknown Source)
    at nmfl.asW.valueChanged(Unknown Source)
    at org.jgraph.JGraph.fireValueChanged(Unknown Source)
    at org.jgraph.JGraph$GraphSelectionRedirector.valueChanged(Unknown Source)
    at org.jgraph.graph.DefaultGraphSelectionModel.fireValueChanged(Unknown Source)
    at org.jgraph.graph.DefaultGraphSelectionModel.notifyCellChange(Unknown Source)
    at org.jgraph.graph.DefaultGraphSelectionModel.removeSelectionCells(Unknown Source)
    at org.jgraph.plaf.basic.BasicGraphUI$GraphModelHandler.graphChanged(Unknown Source)
    at org.jgraph.graph.DefaultGraphModel.fireGraphChanged(Unknown Source)
    at org.jgraph.graph.DefaultGraphModel$GraphModelEdit.execute(Unknown Source)
    at org.jgraph.graph.DefaultGraphModel.remove(Unknown Source)
    at org.jgraph.graph.GraphLayoutCache.remove(Unknown Source)
    at nmfl.DA.a(Unknown Source)
    at nmfl.aFc.a(Unknown Source)
    at nmfl.asE.a(Unknown Source)
    at nmfl.Cd.a(Unknown Source)
    at nmfl.qF.actionPerformed(Unknown Source)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
    at javax.swing.AbstractButton.doClick(AbstractButton.java:357)
    at com.jidesoft.plaf.vsnet.VsnetMenuItemUI.doClick(Unknown Source)
    at com.jidesoft.plaf.vsnet.VsnetMenuItemUI$MouseInputHandler.mouseReleased(Unknown Source)
    at java.awt.Component.processMouseEvent(Component.java:6041)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3265)
    at java.awt.Component.processEvent(Component.java:5806)
    at java.awt.Container.processEvent(Container.java:2058)
    at java.awt.Component.dispatchEventImpl(Component.java:4413)
    at java.awt.Container.dispatchEventImpl(Container.java:2116)
    at java.awt.Component.dispatchEvent(Component.java:4243)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4322)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3986)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3916)
    at java.awt.Container.dispatchEventImpl(Container.java:2102)
    at java.awt.Component.dispatchEvent(Component.java:4243)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)