I have this exact problem on Windows 7 64-bit, R2013a.
I can't use 'help on selection' because of this error. No other symptoms yet.
Error below:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at com.mathworks.helpsearch.product.ProductNameComparator.getSortPriority(ProductNameComparator.java:26) at com.mathworks.helpsearch.product.ProductNameComparator.compare(ProductNameComparator.java:16) at com.mathworks.helpsearch.product.ProductNameComparator.compare(ProductNameComparator.java:7) at com.mathworks.helpsearch.reference.ProductOrderComparator.compare(ProductOrderComparator.java:21) at com.mathworks.helpsearch.reference.ProductOrderComparator.compare(ProductOrderComparator.java:15) at com.mathworks.helpsearch.reference.CompoundReferenceComparator.compare(CompoundReferenceComparator.java:21) at com.mathworks.helpsearch.reference.CompoundReferenceComparator.compare(CompoundReferenceComparator.java:10) at com.mathworks.helpsearch.reference.CompoundReferenceComparator.compare(CompoundReferenceComparator.java:21) at com.mathworks.helpsearch.reference.CompoundReferenceComparator.compare(CompoundReferenceComparator.java:10) at java.util.Arrays.mergeSort(Unknown Source) at java.util.Arrays.mergeSort(Unknown Source) at java.util.Arrays.mergeSort(Unknown Source) at java.util.Arrays.mergeSort(Unknown Source) at java.util.Arrays.sort(Unknown Source) at java.util.Collections.sort(Unknown Source) at com.mathworks.helpsearch.reference.ReferenceDataRetriever.getReferenceData(ReferenceDataRetriever.java:24) at com.mathworks.mlwidgets.help.HelpUtils.getReferenceData(HelpUtils.java:992) at com.mathworks.mlwidgets.help.HelpPopup.getReferenceData(HelpPopup.java:683) at com.mathworks.mlwidgets.help.HelpPopup.getDocCenterReferencePageUrl(HelpPopup.java:670) at com.mathworks.mlwidgets.help.HelpPopup.getReferencePageUrl(HelpPopup.java:665) at com.mathworks.mlwidgets.help.HelpPopup.populateAndShow(HelpPopup.java:620) at com.mathworks.mlwidgets.help.HelpPopup.showHelp(HelpPopup.java:358) at com.mathworks.mlwidgets.help.HelpPopup.showHelp(HelpPopup.java:301) at com.mathworks.mlwidgets.help.HelpPopup.showHelp(HelpPopup.java:193) at com.mathworks.mlwidgets.help.HelpPopup.showHelp(HelpPopup.java:152) at com.mathworks.mde.cmdwin.CmdWinEditorKit$HelpAction.actionPerformed(CmdWinEditorKit.java:1333) at javax.swing.SwingUtilities.notifyAction(Unknown Source) at javax.swing.JComponent.processKeyBinding(Unknown Source) at javax.swing.JComponent.processKeyBindings(Unknown Source) at javax.swing.JComponent.processKeyEvent(Unknown Source) at com.mathworks.mde.cmdwin.XCmdWndView.processKeyEvent(XCmdWndView.java:2541) at java.awt.Component.processEvent(Unknown Source) at java.awt.Container.processEvent(Unknown Source) at com.mathworks.mde.cmdwin.XCmdWndView.processEvent(XCmdWndView.java:420) at java.awt.Component.dispatchEventImpl(Unknown Source) at java.awt.Container.dispatchEventImpl(Unknown Source) at java.awt.Component.dispatchEvent(Unknown Source) at java.awt.KeyboardFocusManager.redispatchEvent(Unknown Source) at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(Unknown Source) at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(Unknown Source) at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(Unknown Source) at java.awt.DefaultKeyboardFocusManager.dispatchEvent(Unknown Source) at java.awt.Component.dispatchEventImpl(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)
