Hello,

When viewing the source of the pages of these themes, we see that there are 3 blank lines before the
<! DOCTYPE html>. (cf attachment snskanta-01.gif)

Visually it does not impact the front side, but once you try to use XML files generated in this problem because these three blank lines fail to validate a valid XML file. (cf attachment snskanta-02.gif)

But in Prestashop Store Page, we need a clean XML file (without empty line) for view correctly Google Map
http://demo.snstheme.com/presta/sns-kanta/en/stores?ajax=1&all=1

When i disabled the module snskantatheme, we are not 3 empty line.

This problème are in your all Pretashop KANTA theme / Gabia Theme / Senia Theme