Program: 188033
Project: 188033
Buggy source:
public void addRemovePlugin(MyButton addremove,String filename){
  File pluginfile=new File(Repository.PLUGINSDIRECTORY + Repository.getBar() + filename);
  if (addremove.getText().equals("String_Node_Str")) {
    GridBagLayout layout=(GridBagLayout)localtable.getLayout();
    GridBagConstraints constraints=layout.getConstraints(addremove);
    GridBagConstraints constraints1=layout.getConstraints(addremove.getMyLabel());
    localtable.remove(addremove);
    localtable.remove(addremove.getMyLabel());
    remotetable2.add(addremove,constraints);
    remotetable2.add(addremove.getMyLabel(),constraints1);
    try {
      ((TwisterPluginInterface)plugins.get(filename)).terminate();
    }
 catch (    Exception e) {
      System.out.println("String_Node_Str" + "String_Node_Str" + filename);
      e.printStackTrace();
    }
    MainPanel main=Repository.window.mainpanel;
    try {
      main.remove(((TwisterPluginInterface)plugins.get(filename)).getContent());
    }
 catch (    Exception e) {
      System.out.println("String_Node_Str" + "String_Node_Str" + filename);
      e.printStackTrace();
    }
    main.revalidate();
    main.repaint();
    localtable.revalidate();
    localtable.repaint();
    remotetable2.revalidate();
    remotetable2.repaint();
    Repository.removePlugin(filename);
    plugins.remove(filename);
    addremove.setText("String_Node_Str");
    plugintable.removeAll();
    Iterator iterator=plugins.keySet().iterator();
    String name;
    String description;
    while (iterator.hasNext()) {
      name=iterator.next().toString();
      TwisterPluginInterface plugin=(TwisterPluginInterface)plugins.get(name);
      description=plugin.getDescription();
      addPlugin(name,description,plugin);
    }
    plugintable.revalidate();
    plugintable.repaint();
  }
 else {
    if (copyPlugin(filename)) {
      addremove.setText("String_Node_Str");
      GridBagLayout layout=(GridBagLayout)remotetable2.getLayout();
      GridBagConstraints constraints=layout.getConstraints(addremove);
      GridBagConstraints constraints1=layout.getConstraints(addremove.getMyLabel());
      remotetable2.remove(addremove);
      remotetable2.remove(addremove.getMyLabel());
      localtable.add(addremove,constraints);
      localtable.add(addremove.getMyLabel(),constraints1);
      localtable.revalidate();
      localtable.repaint();
      remotetable2.revalidate();
      remotetable2.repaint();
      plugintable.removeAll();
      Repository.addPlugin(filename);
      PluginsLoader.setClassPath();
      getPlugins();
      Iterator iterator=plugins.keySet().iterator();
      String name;
      String description;
      while (iterator.hasNext()) {
        name=iterator.next().toString();
        TwisterPluginInterface plugin=(TwisterPluginInterface)plugins.get(name);
        description=plugin.getDescription();
        addPlugin(name,description,plugin);
      }
    }
  }
}

Fixed version (ground truth):
public void addRemovePlugin(MyButton addremove,String filename){
  File pluginfile=new File(Repository.PLUGINSDIRECTORY + Repository.getBar() + filename);
  if (addremove.getText().equals("String_Node_Str")) {
    GridBagLayout layout=(GridBagLayout)localtable.getLayout();
    GridBagConstraints constraints=layout.getConstraints(addremove);
    GridBagConstraints constraints1=layout.getConstraints(addremove.getMyLabel());
    localtable.remove(addremove);
    localtable.remove(addremove.getMyLabel());
    remotetable2.add(addremove,constraints);
    remotetable2.add(addremove.getMyLabel(),constraints1);
    MainPanel main=Repository.window.mainpanel;
    try {
      main.remove(((TwisterPluginInterface)plugins.get(filename)).getContent());
    }
 catch (    Exception e) {
      System.out.println("String_Node_Str" + "String_Node_Str" + filename);
      e.printStackTrace();
    }
    try {
      ((TwisterPluginInterface)plugins.get(filename)).terminate();
    }
 catch (    Exception e) {
      System.out.println("String_Node_Str" + "String_Node_Str" + filename);
      e.printStackTrace();
    }
    main.revalidate();
    main.repaint();
    localtable.revalidate();
    localtable.repaint();
    remotetable2.revalidate();
    remotetable2.repaint();
    Repository.removePlugin(filename);
    plugins.remove(filename);
    addremove.setText("String_Node_Str");
    plugintable.removeAll();
    Iterator iterator=plugins.keySet().iterator();
    String name;
    String description;
    while (iterator.hasNext()) {
      name=iterator.next().toString();
      TwisterPluginInterface plugin=(TwisterPluginInterface)plugins.get(name);
      description=plugin.getDescription();
      addPlugin(name,description,plugin);
    }
    plugintable.revalidate();
    plugintable.repaint();
  }
 else {
    if (copyPlugin(filename)) {
      addremove.setText("String_Node_Str");
      GridBagLayout layout=(GridBagLayout)remotetable2.getLayout();
      GridBagConstraints constraints=layout.getConstraints(addremove);
      GridBagConstraints constraints1=layout.getConstraints(addremove.getMyLabel());
      remotetable2.remove(addremove);
      remotetable2.remove(addremove.getMyLabel());
      localtable.add(addremove,constraints);
      localtable.add(addremove.getMyLabel(),constraints1);
      localtable.revalidate();
      localtable.repaint();
      remotetable2.revalidate();
      remotetable2.repaint();
      plugintable.removeAll();
      Repository.addPlugin(filename);
      PluginsLoader.setClassPath();
      getPlugins();
      Iterator iterator=plugins.keySet().iterator();
      String name;
      String description;
      while (iterator.hasNext()) {
        name=iterator.next().toString();
        TwisterPluginInterface plugin=(TwisterPluginInterface)plugins.get(name);
        description=plugin.getDescription();
        addPlugin(name,description,plugin);
      }
    }
  }
}