HTACCESS broke PHP code and the Xampp server - php

Question

After 450 hours of work my web-app doesn't work anymore, and I don't know how to solve it. Let me explain the situation:
I was inserting my website into the server and playing around with htaccess.
I have changed many times the htaccess playing around with symlinks, rewriting url to go to redirect to https, etc.
My website was logging in the user and now not anymore working for this function anymore:
The Apache log is this one repeating the same name of the folder:
[13/Oct/2017:21:44:59 +0200] "GET
/developement/index.php/fold/fold/fold/fold/fold/fold/loginform.inc.php
HTTP/1.1" 302 9358 "-" "Mozilla/5.0 (Windows NT 6.2; WOW64;
Trident/7.0; rv:11.0) like Gecko"
I have just changed the httpd.conf in Xampp inserting: AllowOverride All
after I discovered it was on none
I don't really know what's going on:
I think I have a problem in my php where I write the header:
header("Location: ../invoice.php"); if the user is logging in.
I have read that you can't have any echo in the php file before header if not is not working
Further info:
I have included a core.php file in all the files so I define some functionlike the below:
<?
ob_start();//to use the header func to redirect to index.php after log in
session_name("test");//to hide session id def cookie name PHPSESSID=
session_start();//to save the global var user id after log in
//Errors On/off
if(strstr($_SERVER['SERVER_NAME'],"localhost")) {
// Make sure we show all errors
ini_set('display_errors', 1);
ini_set('log_errors', 1);
error_reporting(E_ALL);
ini_set('html_errors', 'On');
ini_set('display_startup_errors','On');
} else {
//IMP: DA VERIFICARE SE FUNZIONA NEL SERVER!!!!!!!!!!!!!!!!!!!
// We also want to suppress all warnings
ini_set('display_errors', 0);
error_reporting(0);
ini_set('html_errors', 'Off');
ini_set('display_startup_errors','Off');
}
//this to define links in my HTML (in header(Location: MIO./myfolder ) it does not work !!!)
//define http root
define("MINE",($_SERVER["SERVER_NAME"] == "localhost")? "http://localhost/developement/" : "https://www.mywebsite.it/");
//echo MINE;
?>
Content of .htaccess:
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteCond %{HTTP_HOST} ^mywebsite.it [OR]
RewriteCond %{HTTP_HOST} ^www.mywebsite.it [NC]
RewriteRule ^(.*)$ https://www.mywebsite.it/$1 [L,R=301]
Xampp Apache Access Log:
::1 - - [15/Oct/2017:00:47:10 +0200] "POST /developement/elgin/loginform.inc.php HTTP/1.1" 200 10325 "http://localhost/developement/elgin/loginform.inc.php" "Mozilla/5.0 (Windows NT 6.2; WOW64; Trident/7.0; rv:11.0) like Gecko"
Xampp Apache Error Log:
Failed loading C:\xampp\php\ext\php_xdebug-2.5.4-7.1-vc14.dll
6] AH01909: www.example.com:443:0 server certificate does NOT include an ID which matches the server name

Answer 1

Just some php files had the BOM.
Saved to BOM and re-saved to UTF-8 w no BOM