Program: 169581
Project: 169581
Buggy source:
@Override public void initGui(){
  super.initGui();
  int x=this.guiLeft + 10;
  int y=this.guiTop + 20;
  if (!editMode) {
    if (controller.launcherData != null) {
      String launcherName=LanguageUtility.getLocalName("String_Node_Str");
      String siloName=LanguageUtility.getLocalName("String_Node_Str");
      for (int i=0; i < controller.launcherData.size(); i++) {
        buttons=new GuiButton[controller.launcherData.size() * 2];
        String buttonName=launcherName;
        String name="String_Node_Str" + i;
        ITileNode tile=controller.launcherData.get(i).location.getTileNode(controller.world());
        if (tile instanceof TileAbstractLauncher) {
          if (tile instanceof TileSmallSilo || tile instanceof TileStandardSilo) {
            buttonName=siloName;
          }
          String n=((TileAbstractLauncher)tile).getCustomName();
          if (n != null && !n.isEmpty() && !n.equals("String_Node_Str")) {
            if (n.length() > 12) {
              n=n.substring(0,11) + "String_Node_Str";
            }
            name=n;
          }
        }
        buttonName+="String_Node_Str" + name + "String_Node_Str";
        buttons[i]=new GuiButton(i,x,y,120,20,buttonName);
        this.buttonList.add(buttons[i]);
        buttons[i + controller.launcherData.size()]=new GuiButton(i + controller.launcherData.size(),x + 125,y,30,20,LanguageUtility.getLocalName("String_Node_Str"));
        if (controller.launcherData.get(i).missile == null) {
          buttons[i + controller.launcherData.size()].enabled=false;
        }
        this.buttonList.add(buttons[i + controller.launcherData.size()]);
        y+=22;
      }
    }
  }
 else {
    this.buttonList.add(new GuiButton(0,x + 65,y + 85,30,20,LanguageUtility.getLocalName("String_Node_Str")));
    this.buttonList.add(new GuiButton(1,x + 100,y + 85,50,20,LanguageUtility.getLocalName("String_Node_Str")));
    x=guiLeft + 10;
    y=guiTop + 42;
    ITileNode tile=controller.launcherData.get(editMissile).location.getTileNode(controller.world());
    if (tile instanceof TileAbstractLauncher && ((TileAbstractLauncher)tile).target != null) {
      this.x_field=this.newField(x,y,40,20,"String_Node_Str" + ((TileAbstractLauncher)tile).target.xi());
      this.y_field=this.newField(x + 45,y,40,20,"String_Node_Str" + ((TileAbstractLauncher)tile).target.yi());
      this.z_field=this.newField(x + 90,y,40,20,"String_Node_Str" + ((TileAbstractLauncher)tile).target.zi());
      this.name_field=this.newField(x,y + 38,90,20,((TileAbstractLauncher)tile).getCustomName() != null ? ((TileAbstractLauncher)tile).getCustomName() : "String_Node_Str");
    }
  }
}

Fixed version (ground truth):
@Override public void initGui(){
  super.initGui();
  int x=this.guiLeft + 10;
  int y=this.guiTop + 20;
  if (!editMode) {
    if (controller.launcherData != null) {
      String launcherName=LanguageUtility.getLocalName("String_Node_Str");
      String siloName=LanguageUtility.getLocalName("String_Node_Str");
      for (int i=0; i < controller.launcherData.size(); i++) {
        buttons=new GuiButton[controller.launcherData.size() * 2];
        String buttonName=launcherName;
        String name="String_Node_Str" + i;
        ITileNode tile=controller.launcherData.get(i).location.getTileNode(controller.world());
        if (tile instanceof TileAbstractLauncher) {
          if (tile instanceof TileSmallSilo || tile instanceof TileStandardSilo) {
            buttonName=siloName;
          }
          String n=((TileAbstractLauncher)tile).getCustomName();
          if (n != null && !n.isEmpty() && !n.equals("String_Node_Str")) {
            if (n.length() > 12) {
              n=n.substring(0,11) + "String_Node_Str";
            }
            name=n;
          }
        }
        buttonName+="String_Node_Str" + name + "String_Node_Str";
        buttons[i]=new GuiButton(i,x,y,120,20,buttonName);
        this.buttonList.add(buttons[i]);
        buttons[i + controller.launcherData.size()]=new GuiButton(i + controller.launcherData.size(),x + 125,y,30,20,LanguageUtility.getLocalName("String_Node_Str"));
        if (controller.launcherData.get(i).missile == null) {
          buttons[i + controller.launcherData.size()].enabled=false;
        }
        this.buttonList.add(buttons[i + controller.launcherData.size()]);
        y+=22;
      }
    }
  }
 else {
    this.buttonList.add(new GuiButton(0,x + 65,y + 85,30,20,LanguageUtility.getLocalName("String_Node_Str")));
    this.buttonList.add(new GuiButton(1,x + 100,y + 85,50,20,LanguageUtility.getLocalName("String_Node_Str")));
    x=guiLeft + 10;
    y=guiTop + 42;
    Pos location=controller.launcherData.get(editMissile).location;
    ITileNode tile=location.getTileNode(controller.world());
    if (tile instanceof TileAbstractLauncher && ((TileAbstractLauncher)tile).target != null) {
      this.x_field=this.newField(x,y,40,20,"String_Node_Str" + ((TileAbstractLauncher)tile).target.xi());
      this.y_field=this.newField(x + 45,y,40,20,"String_Node_Str" + ((TileAbstractLauncher)tile).target.yi());
      this.z_field=this.newField(x + 90,y,40,20,"String_Node_Str" + ((TileAbstractLauncher)tile).target.zi());
      this.name_field=this.newField(x,y + 38,90,20,((TileAbstractLauncher)tile).getCustomName() != null ? ((TileAbstractLauncher)tile).getCustomName() : "String_Node_Str");
    }
  }
}