J-BusinessDirectory - Paypal - Where am I going wrong?

I left Paypal as my only method of payment, including excluding others. I left the settings below:

https://www.oficinascuritiba.com.br/bruno/configs_paypal.jpg

OK! It's working! The person selects the package, fills in the information, and then moves on to the payment screen. The site redirects to Paypal, where it makes the payment ... and so far so good also, the payment is being made and I'm receiving!

The problem is the time to return to the site. When the person clicks "back to seller's site" there in PayPal, it just happens:

https://www.oficinascuritiba.com.br/bruno/ERRO_PAYPAL.jpg 

It does not return to the site. What am I doing wrong? Did i have to configure something more? Or is it in Paypal itself? What do I have to do exactly?

Hi,

The response URL does not contain the extension name and that's why you receive the error.
This can happen if the return URL has been modified in code or if the option parameter is removed by joomla.
Return url is defined is the following way.
$this->returnUrl = JRoute::_("index.php?option=com_jbusinessdirectory&task=$controller.processResponse&processor=paypal",false,-1);