This occurs in TextArea.java and JTextArea.java

    static {
        /* ensure that the necessary native libraries are loaded */
        Toolkit.loadLibraries();
        initIDs();
        forwardTraversalKeys = KeyboardFocusManager.loadFocusTraversalKeys
            ("AWT.forwardTextAreaFocusTraversalKey", "ctrl TAB",
             new TreeSet());
        backwardTraversalKeys = KeyboardFocusManager.loadFocusTraversalKeys
            ("AWT.bacwardTextAreaFocusTraversalKey", "ctrl shift TAB",
             new TreeSet());
    }

It should be "AWT.backwardTextAreaFocusTraversalKey" - the k is missing
in the string above.