java NullPointerException on clicking on Workspace

Hi, I'm running R2012a on OSX Yosemite(10.10.5). Every time I click on a variable in the Workspace panel, I get the following erros (+stack trace). It's inconvenient because after the error appeared once, the same thing appears after any operation that I do. I'm not sure when it started, but I think it wasn't directly related to installing Yosemite.

Do you have any suggestions?

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at com.mathworks.widgets.WindowsWidgetFactory$SearchAndClearButton.anyText(WindowsWidgetFactory.java:187) at com.mathworks.widgets.WindowsWidgetFactory$SearchAndClearButton.getIcon(WindowsWidgetFactory.java:195) at com.apple.laf.AquaButtonUI.setThemeBorder(AquaButtonUI.java:91) at com.apple.laf.AquaButtonUI.installDefaults(AquaButtonUI.java:58) at javax.swing.plaf.basic.BasicButtonUI.installUI(BasicButtonUI.java:71) at javax.swing.JComponent.setUI(JComponent.java:670) at javax.swing.AbstractButton.setUI(AbstractButton.java:1815) at javax.swing.JButton.updateUI(JButton.java:128) at javax.swing.AbstractButton.init(AbstractButton.java:2182) at javax.swing.JButton.<init>(JButton.java:118) at javax.swing.JButton.<init>(JButton.java:73) at com.mathworks.mwswing.MJButton.<init>(MJButton.java:73) at com.mathworks.widgets.WindowsWidgetFactory$SearchAndClearButton.<init>(WindowsWidgetFactory.java:153) at com.mathworks.widgets.WindowsWidgetFactory$SearchAndClearButton.<init>(WindowsWidgetFactory.java:167) at com.mathworks.widgets.WindowsWidgetFactory.createSearchAndClearButton(WindowsWidgetFactory.java:58) at com.mathworks.widgets.SearchTextField.buildDefaultComponent(SearchTextField.java:517) at com.mathworks.widgets.SearchTextField.buildComponent(SearchTextField.java:480) at com.mathworks.widgets.SearchTextField.init(SearchTextField.java:182) at com.mathworks.widgets.SearchTextField.<init>(SearchTextField.java:173) at com.mathworks.widgets.SearchTextField.<init>(SearchTextField.java:160) at com.mathworks.widgets.SearchTextField.<init>(SearchTextField.java:122) at com.mathworks.mlwidgets.graphics.PlotPickerPanel.init(PlotPickerPanel.java:580) at com.mathworks.mlwidgets.graphics.PlotPickerPanel.<init>(PlotPickerPanel.java:87) at com.mathworks.mlwidgets.graphics.PlotPicker.createPlotPickerPanel(PlotPicker.java:152) at com.mathworks.mlwidgets.graphics.PlotPicker.utSetPlottedVars(PlotPicker.java:482) at com.mathworks.mlwidgets.graphics.PlotPicker.access$700(PlotPicker.java:23) at com.mathworks.mlwidgets.graphics.PlotPicker$PlotPickerUIUpdater.run(PlotPicker.java:601) at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:715) at java.awt.EventQueue.access$400(EventQueue.java:82) at java.awt.EventQueue$2.run(EventQueue.java:676) at java.awt.EventQueue$2.run(EventQueue.java:674) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:86) at java.awt.EventQueue.dispatchEvent(EventQueue.java:685) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188) at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)