Julien Polycarpe

Hello everyone, I installed the stripe module on my website(Prestashop 1.7, Stripe module 2.0.8 and PHP 7.1.30) but I can't make it work. When I fullfill a payment with a 4242 4242 4242 4242 test card by clicking on my final "buy" button, the button's text changes to processing... and keeps looping infinitely. In debug mode, I get this error (POST 500) here: mywebsite.com/modules/stripe_official/validation. Moreover, if I refresh, my cart is now empty and my order appears as : payment successfull in my backend panel. I found no way to solve this on the Internet. Does someone know how to solve this please? Thank you very much, Julien Polycarpe