Error using optim toolbox in MATLAB 2015a.

Error using optimtool (line 168)

Java exception occurred:

java.lang.NoClassDefFoundError: Could not initialize class com.mathworks.mlwidgets.help.ProductFilterModel$InstalledState

at com.mathworks.mlwidgets.help.DocCenterProductPrefs.getSelectedProductsFromPref(DocCenterProductPrefs.java:47)

at com.mathworks.mlwidgets.help.DocCenterProductPrefs.getProductFilterModel(DocCenterProductPrefs.java:33)

at com.mathworks.mlwidgets.help.DocCenterDocConfigParams.<init>(DocCenterDocConfigParams.java:37)

at com.mathworks.mlwidgets.help.DocCenterDocConfig.getLocalConfig(DocCenterDocConfig.java:77)

at com.mathworks.mlwidgets.help.DocCenterDocConfig.getInstance(DocCenterDocConfig.java:65)

at com.mathworks.mlwidgets.help.HelpPanel.<init>(HelpPanel.java:142)

at com.mathworks.mlwidgets.help.HelpPanel.<init>(HelpPanel.java:122)

at com.mathworks.mlwidgets.help.HelpPanel.<init>(HelpPanel.java:107)

at com.mathworks.mlwidgets.help.HelpPanel.<init>(HelpPanel.java:94)

at com.mathworks.mlwidgets.help.HelpPanel.<init>(HelpPanel.java:82)

at com.mathworks.mlwidgets.help.HelpPanel.<init>(HelpPanel.java:72)

at com.mathworks.mlwidgets.help.HelpPanel.<init>(HelpPanel.java:62)

at com.mathworks.toolbox.optim.OptimGUIPanels.<init>(OptimGUIPanels.java:32)

at com.mathworks.toolbox.optim.OptimGUI.<init>(OptimGUI.java:376)

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)

at java.lang.reflect.Constructor.newInstance(Unknown Source)

at com.mathworks.jmi.AWTUtilities$Invoker$4$1.call(AWTUtilities.java:561)

at com.mathworks.mvm.context.ThreadContext.callWithContext(ThreadContext.java:105)

at com.mathworks.mvm.context.MvmContext.callWithContext(MvmContext.java:113)

at com.mathworks.jmi.AWTUtilities$Invoker$4.runWithOutput(AWTUtilities.java:558)

at com.mathworks.jmi.AWTUtilities$Invoker$2.watchedRun(AWTUtilities.java:475)

at com.mathworks.jmi.AWTUtilities$WatchedRunnable.run(AWTUtilities.java:436)

at java.awt.event.InvocationEvent.dispatch(Unknown Source)

at java.awt.EventQueue.dispatchEventImpl(Unknown Source)

at java.awt.EventQueue.access$200(Unknown Source)

at java.awt.EventQueue$3.run(Unknown Source)

at java.awt.EventQueue$3.run(Unknown Source)

at java.security.AccessController.doPrivileged(Native Method)

at java.security.ProtectionDomain$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)