title: PHP FIle not found when i submit a form
body: <p>Good Day.
  So, i have, after testing on a local WAMP server, deployed my site on a server and after i fill in my form and submit it, i get the "File not found" warning as well as  blank page on the referred php file. i am not sure what could cause this. as i have extensively tested this on my local server without any hitches. </p>
  
  <pre><code>                    &lt;form  action = "submit.php"  method="Post" &gt;
                      &lt;div class="row form-group"&gt;
                          &lt;div class="col-md-12"&gt;
                              &lt;!-- &lt;label for="email"&gt;Email&lt;/label&gt; --&gt;
                              &lt;input type="text" id="email" autocomplete="off"  name="email" class="form-control" placeholder="Your Email"&gt;
                          &lt;/div&gt;
                      &lt;/div&gt;
  
                      &lt;div class="row form-group"&gt;
                          &lt;div class="col-md-12"&gt;
                              &lt;!-- &lt;label for="subject"&gt;Subject&lt;/label&gt; --&gt;
                              &lt;input type="text" autocomplete="off" id="password"  name="password" class="form-control" placeholder="Your Password"&gt;
                          &lt;/div&gt;
                      &lt;/div&gt;
  
                      &lt;div class="form-group"&gt;
                          &lt;input type="submit" value="Login" class="btn btn-primary"&gt;
                      &lt;/div&gt;
  
                  &lt;/form&gt;     
  </code></pre>
  
  <p>And here is the submit.php</p>
  
  <pre><code>&lt;?php
  session_start();
  require_once('connect.php');
  if(isset($_POST) &amp; !empty($_POST)){
      $useremail = mysqli_real_escape_string($connection,$_POST['email']);
      $userpassword = mysqli_real_escape_string($connection, $_POST['password']); 
      if (empty($useremail) || empty($userpassword)){
          header("Location: customerportal.php?login=empty");
          exit();
      }
      else{       
                  $sql = "SELECT * FROM `USERS` where EMAIL = '$useremail';";
                  $currenttime = date("Y-m-d H:i:s");
                  $sqllastlogin = "UPDATE `users` SET `LASTLOGIN` = '$currenttime' where EMAIL = '$useremail';";
                  $lastlogin = mysqli_query($connection,$sqllastlogin);
                  $emailresult = mysqli_query($connection, $sql);
                  $emailresultcheck = mysqli_num_rows($emailresult);
                  //check if email exists
  
  
                  if($emailresultcheck == 0){
                      header("Location: customerportal.php?login=invalidEmail");
                  }
                  else {                  
                      if($row = mysqli_fetch_assoc($emailresult)){
  
                          //dehash the password
                          $hashedPWDCheck = password_verify($userpassword,$row['ENCRYPTEDPWD']);
                          $isAdmin = $row['DHCADMIN'];
                          if($hashedPWDCheck == false){
                              header("Location: customerportal.php?login=passwordincorrect");
                              exit();
                          }
                          elseif($hashedPWDCheck == true){
                              $_SESSION['email'] = $useremail;
                              $_SESSION['username'] = $row['username'];
                              $_SESSION['entityname'] = $row['COMMERCIALTNITY_ID'];
                              $_SESSION['isAdmin'] = $isAdmin;
  
                              if($isAdmin == 1){
                                  header("Location: admin.php");
                                  exit();
                              }
                              elseif($isAdmin == 0){
                                header("Location: landingpage.php");
                                exit();
                              }
  
                          }
                  }
  
                  else{
                      header("Location: customerportal.php?login=invalid");   
                      exit(); 
                      }
                  }               
      }   
  }   
  ?&gt;
  </code></pre>
  
  <p>Can you guys please assist.
  Here is the fodler structure of the server.
  <a href="https://i.stack.imgur.com/IZpCm.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IZpCm.jpg" alt="enter image description here"></a></p>