Hola. Estoy intentando crear un sitio web solo para miembros. Intento crear un script con sesiones, etc. Sin embargo, cuando hago clic en el botón de inicio de sesión, aparece el siguiente error:

Warning: Unknown: failed to open stream: No such file or directory in Unknown on line 0

Fatal error: Unknown: Failed opening required 'prepend.php' (include_path='.:/Applications/XAMPP/xamppfiles/lib/php') in Unknown on line 0

No estoy 100% seguro de lo que significa todo esto, así que publicaré mi guión y apreciaría si alguien pudiera decirme en profundidad dónde me equivoco para poder comprender y aprender para el futuro lo que estoy haciendo mal. .

Gracias de antemano por cualquier entrada y ayuda.

index.php

<div id="maincontentWrapper">
<div id="maincontent">
    <div id="contentWrapper"></div><!--End loginWrapper -->
        <article>
            <p>Welcome to iManage, please login in below.</p>
        </article>
    <div id="loginform">
        <div id="loginWrapper">
        <form id="loginForm" method="POST" action="classes/class.Login.php">
        <h1><span class="log-in">Log in</span> or <span class="sign-up"><a href="register">sign up</a></span></h1>
        <div id="errorDiv"><?php 
                    if (isset($_SESSION['error']) & isset($_SESSION['formAttempt'])) {
                            unset($_SESSION['formAttempt']);
                            print "Errors encountered<br/>\n";
                            foreach ($_SESSION['error'] as $error) {
                            print $error . "<br />\n";
                        } //end foreach
                        } //end if 
                ?></div>
    <p class="float">
        <label for="login"><i class="icon-user"></i>Username</label>
        <input type="text" id="email" name="email" placeholder="E-mail">
          <span class="errorFeedback errorSpan" id="emailError">E-mail is required</span>
    </p>
    <p class="float">
        <label for="password"><i class="icon-lock"></i>Password</label>
        <input type="password" id="password" name="password" placeholder="Password" class="showpassword"> 
                <span class="errorFeedback errorSpan" id="passwordError">Password is required</span>

    </p>
    <p class="clearfix"> 
        <input type="submit" name="submit" value="Log in"></form>
    </p>   
        </div>

    </div>


</div>
</div>

</div>

classes / class.Login.php

<?php 
include("../connect/class.Connect.php");

class Login extends Database {

    public $id;
    public $email;
    public $username;

        public function __construct() {
            if (session_id() == "") {
                session_start();    
            }
            if (isset($_SESSION['isLoggedIn']) && $_SESSION['isLoggedIn'] == true) {
                $this->_initUser();     
            }

        } // end construct

        public function authenticate($user, $pass) {

            $safeUser = $this->mysqli->real_escape_string($pass);
            $query = "SELECT * from users WHERE email = '{$safeUser}'";

                if (!$result = $this->mysqli->query($query)) {
                        error_log("Cannot retrieve account for {$user}");
                        return false;
                }   

                // will be only one row, so no while() loop needed
                $row = $result->fetch_assoc();
                $dbPassword = $row['password'];

                if (crypt($incomingPassword,$dbPassword) != $dbPassword) {
                        error_log("Passwords for {$user} don't match");
                        return false;
                }
                    $this->id = $row['id'];
                    $this->username = $row['username'];
                    $this->email = $row['email'];
                    $this->isLoggedIn = true;

                    $this->_setSession();
                    return true;    
        } // end function autheticate


        private function _setSession() {

            if (session_id() == '') {
                session_start();    
            }

            $_SESSION['id'] = $this->id;
            $_SESSION['email'] = $this->email;
            $_SESSION['username'] = $this->username;
            $_SESSION['isLoggedIn'] = $this->isLoggedIn;

        } // end function setSession

        private function _initUser() {

            if(session_id() == '') {
                sessions_start();           
            }

            $_SESSION['id'] = $this->id;
            $_SESSION['email'] = $this->email;
            $_SESSION['username'] = $this->username;
            $_SESSION['isLoggedIn'] = $this->isLoggedIn;



        }// end function initUser

        function validatelogin () {
                    $_SESSION['formAttempt'] = true;

        if (isset($_SESSION['error'])) {
        unset($_SESSION['error']);
        }

         $_SESSION['error'] = array();

        $required = array("email","password");

            //Check required fields
            foreach ($required as $requiredField) {
            if (!isset($_POST[$requiredField]) || $_POST[$requiredField] == "") {
            $_SESSION['error'][] = $requiredField . " is required.";
            }
            }


            if (!filter_var($_POST['email'],FILTER_VALIDATE_EMAIL)) {
            $_SESSION['error'][] = "Invalid e-mail address";
            }

            if (count($_SESSION['error']) > 0) {
                die(header("Location: login.php")); 
            } else {
                $user = new User;
                if ($user->authenciate($_POST['email'], $_POST['password'])) {
                    unset($_SESSION['formAttempt']);    
                 die(header("Location: authenticated.php"));
            }else {
                 $_SESSION['error'][] = "There was a  problem with your username or password.";
                 die(header("Location: login.php"));
                }
        }
        }



}

$run = new Login();
    $run->authenticate($user, $pass);
    $run->validatelogin();
?>

prepend.php

<?php

if (!isset($_SESSION) ) {
session_start();    
}
?>

.htaccess

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.php -f
RewriteRule ^(.*)$ $1.php
php_value auto_prepend_file "prepend.php"