Can't Test the game or add frames to new actors

Unexpected problem on thread AWT-EventQueue-0: null
java.lang.NullPointerException
   at stencyl.core.lib.Atlas.memoryUsageUpdated(Atlas.java:215)
   at stencyl.sw.app.doc.Workspace.onDeleteResource(Workspace.java:911)
   at stencyl.sw.app.doc.Workspace.broadcastEvent(Workspace.java:840)
   at stencyl.sw.app.center.AbstractPage.delete(AbstractPage.java:1413)
   at stencyl.sw.app.lists.AbstractList.mousePressed(AbstractList.java:379)
   at java.awt.AWTEventMulticaster.mousePressed(Unknown Source)
   at java.awt.AWTEventMulticaster.mousePressed(Unknown Source)
   at java.awt.Component.processMouseEvent(Unknown Source)
   at javax.swing.JComponent.processMouseEvent(Unknown Source)
   at stencyl.sw.app.lists.AbstractList.processMouseEvent(AbstractList.java:282)
   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.dispatchEventImpl(Unknown Source)
   at java.awt.EventQueue.access$000(Unknown Source)
   at java.awt.EventQueue$1.run(Unknown Source)
   at java.awt.EventQueue$1.run(Unknown Source)
   at java.security.AccessController.doPrivileged(Native Method)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
   at java.awt.EventQueue$2.run(Unknown Source)
   at java.awt.EventQueue$2.run(Unknown Source)
   at java.security.AccessController.doPrivileged(Native Method)
   at java.security.AccessControlContext$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)


I have a feeling this is a problem.  What can I do to fix it?