code: static void showError(Exception e) {
      String stackTrace = org.languagetool.tools.Tools.getFullStackTrace(e);
      String msg = "<html><p style='width: 600px;'>" + StringTools.escapeHTML(stackTrace);
      JOptionPane.showMessageDialog(null, msg, "Error", JOptionPane.ERROR_MESSAGE);
      e.printStackTrace();
    }
docs: Show the exception (with stacktrace) in a dialog and print it to STDERR.