java.lang.IllegalArgumentException: http://www.jsc.nildram.co.uk/api/index.html is not a valid classpath entry; it must end with a slash.
   at org.netbeans.modules.java.classpath.SimplePathResourceImplementation.verify(SimplePathResourceImplementation.java:108)
   at org.netbeans.modules.java.classpath.SimplePathResourceImplementation.verify(SimplePathResourceImplementation.java:68)
   at org.netbeans.modules.java.classpath.SimplePathResourceImplementation.<init>(SimplePathResourceImplementation.java:126)
   at org.netbeans.spi.java.classpath.support.ClassPathSupport.createResource(ClassPathSupport.java:77)
   at org.netbeans.spi.java.classpath.support.ClassPathSupport.createClassPath(ClassPathSupport.java:147)
   at org.netbeans.modules.javadoc.search.JavadocRegistry.getDocRoots(JavadocRegistry.java:132)
   at org.netbeans.modules.javadoc.search.IndexBuilder.refreshIndex(IndexBuilder.java:183)
   at org.netbeans.modules.javadoc.search.IndexBuilder.run(IndexBuilder.java:129)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1432)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2042)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.IllegalArgumentException: http://www.jsc.nildram.co.uk/api/index.html is not a valid classpath entry; it must end with a slash.
   at org.openide.util.RequestProcessor$Task.schedule(RequestProcessor.java:1473)
   at org.netbeans.modules.javadoc.search.IndexBuilder.scheduleTask(IndexBuilder.java:306)
   at org.netbeans.modules.javadoc.search.IndexBuilder.getDefault(IndexBuilder.java:124)
   at org.netbeans.modules.javadoc.search.IndexOverviewAction$IndexMenu.getPopupMenu2(IndexOverviewAction.java:146)
   at org.netbeans.modules.javadoc.search.IndexOverviewAction$IndexMenu$1.stateChanged(IndexOverviewAction.java:119)
   at javax.swing.DefaultButtonModel.fireStateChanged(DefaultButtonModel.java:349)
   at javax.swing.DefaultButtonModel.setSelected(DefaultButtonModel.java:232)
   at javax.swing.JMenu.setSelected(JMenu.java:311)
   at javax.swing.JMenu.menuSelectionChanged(JMenu.java:1190)
   at javax.swing.MenuSelectionManager.setSelectedPath(MenuSelectionManager.java:118)
   at javax.swing.plaf.basic.BasicMenuUI$Handler.mouseEntered(BasicMenuUI.java:511)
   at java.awt.Component.processMouseEvent(Component.java:6514)
   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(LightweightDispatcher.java:4832)
   at java.awt.LightweightDispatcher.trackMouseEnterExit(LightweightDispatcher.java:4620)
   at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4474)
   at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.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(AccessController.java:0)
   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(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
   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)