SQL Developer fails with IllegalAccessError IdeURLStreamHandler

You installed SQL Developer, created new connection, connected and tried to 
open SQL Worksheet but received the following error:

java.lang.IllegalAccessError: tried to access class 
oracle.ide.net.IdeURLStreamHandler from class oracle.ide.net.URLFileSystem$1
    at oracle.ide.net.URLFileSystem$1.createURLStreamHandler(URLFileSystem.java:87)
    at oracle.ide.boot.URLStreamHandlerFactoryQueue.createURLStreamHandler(URLStreamHandlerFactoryQueue.java:119)
    at java.net.URL.getURLStreamHandler(URL.java:1104)
    at java.net.URL.<init>(URL.java:393)
    at java.net.URL.<init>(URL.java:283)
    at oracle.ide.net.URLFactory.newURL(URLFactory.java:636)
    at oracle.ide.net.URLFactory.newURL(URLFactory.java:136)
    at oracle.dbtools.sqlworksheet.sqlview.SqlEditorNode.<init>(SqlEditorNode.java:70)
    at oracle.dbtools.sqlworksheet.sqlview.SqlEditor.openNewEditor(SqlEditor.java:1978)
    at oracle.dbtools.sqlworksheet.sqlview.SqlEditor.openNewEditor(SqlEditor.java:2037)
    at oracle.dbtools.sqlworksheet.sqlview.SqlEditor.openNewEditor(SqlEditor.java:2055)
    at oracle.dbtools.sqlworksheet.sqlview.SqlEditorWizard.invoke(SqlEditorWizard.java:114)
    at oracle.ide.wizard.WizardManager.invokeWizard(WizardManager.java:310)
    at oracle.dbtools.sqlworksheet.sqlview.SqlEditorController.toolbarAction(SqlEditorController.java:1013)
    at oracle.dbtools.sqlworksheet.sqlview.SqlEditorController.handleEvent(SqlEditorController.java:562)
    at oracle.ide.controller.IdeAction.performAction(IdeAction.java:551)
    at oracle.ide.controller.IdeAction$2.run(IdeAction.java:804)
    at oracle.ide.controller.IdeAction.actionPerformedImpl(IdeAction.java:823)
    at oracle.ide.controller.IdeAction.actionPerformed(IdeAction.java:521)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1849)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2169)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:420)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:258)
    at javax.swing.AbstractButton.doClick(AbstractButton.java:302)
    at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1000)
    at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:1041)
    at java.awt.Component.processMouseEvent(Component.java:5488)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3126)
    at java.awt.Component.processEvent(Component.java:5253)
    at java.awt.Container.processEvent(Container.java:1966)
    at java.awt.Component.dispatchEventImpl(Component.java:3955)
    at java.awt.Container.dispatchEventImpl(Container.java:2024)
    at java.awt.Component.dispatchEvent(Component.java:3803)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4212)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3892)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3822)
    at java.awt.Container.dispatchEventImpl(Container.java:2010)
    at java.awt.Window.dispatchEventImpl(Window.java:1774)
    at java.awt.Component.dispatchEvent(Component.java:3803)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
    at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)

Restart SQL Developer - yep that's it - just like MS Windows.  Congratulations 
ORACLE - you've officially reached the level of Microsoft.  Awesome!