X-Cart forums - Clone slots functionality

I just wrote a module that adds Clone button to 'admin.php?target=slots'. This button copies selected slots(including their images, default products, including products...).
But after upgrade to 5.2.11 xcart version clone button do not copy images(image link is broken).
When I look into log file(/var/log/xlite.log.2016-01-28.php) I see this error:

Code:

Jan 28 10:22:14 XLite [error] Unable to get at the contents of 'https://37.48.94.34/xcart/images/slots/t-shirt-icon.png'.

Runtime id: 8c794e976694c29259b9b253cdea3182;

Server API: apache2handler; IP: 88.135.80.93;

Request method: POST;

URI: /xcart/admin.php?target=slots;

Backtrace:

        file <compiled classes repository>/classes/XLite/Model/Base/Image.php : 160

        file <compiled classes repository>/classes/XLite/Module/Romas/CloneSlots/Controller/Admin/Slots.php : 84

        file <compiled classes repository>/classes/XLite/Controller/AControllerAbstract.php : 1370

        file <compiled classes repository>/classes/XLite/Controller/Admin/AAdmin.php : 269

        file <compiled classes repository>/classes/XLite/Controller/AControllerAbstract.php : 1389

        file <compiled classes repository>/classes/XLite/Controller/AControllerAbstract.php : 557

        file <compiled classes repository>/classes/XLite/Module/QSL/CloudSearch/Controller/AController.php : 49

        file <compiled classes repository>/classes/XLite/Controller/Admin/AAdmin.php : 164

        file <compiled classes repository>/classes/XLiteAbstract.php : 604

        file <compiled classes repository>/classes/XLiteAbstract.php : 629

        file <X-Cart root>/admin.php : 39

84th line of /classes/XLite/Module/Romas/CloneSlots/Controller/Admin/Slots.php corresponds to this code snippet "$new_img = $img->cloneEntity();" :

PHP Code:


		
			
$img = $slot->image;
                    if($img){
                        $new_img = $img->cloneEntity();
                        $new_img->slot = $new_slot;
                        \XLite\Core\Database::getEM()->persist($new_img);
                        \XLite\Core\Database::getEM()->flush();
                    }

Please help me to resolve this issue!
Thanks.