where to put php.ini exactly ?

I am not really sure of what you mean by "changed the dir structure", I think I didn't touch a lot in this ; I have just removed the index.php off the urls, and modified the route.cfg accordingly (with multi-languages scheme too), but elsewhere it works fine.

And yes, the errors appear when I put the php.ini in this same folder as index.php, when I put it in the controllers or in the views, no error, but no effect -)