I have a Prestashop v1.6.1.3 and I installed Paypal official module from Prestashop (v3.11.4).
This module appears broken on screen and completely inoperative. It seems like javascript is broken, this is a screen capture of it. I don detect any javascript or PHP errors on logs, more than this one on JS console:
This page includes a password or credit card input in a non-secure context. A warning has been added to the URL bar. For more information, see https://mobdro.io/
This happens both in Firefox and Chromium. I installed it in different ways, downloading it from Prestashop addons or installing directly from addon list in shop admin panel.