title: When input type file is included, form is not submitted
body: <p>I am trying to upload an image file, it was working well one day before.</p>
  
  <p>Today, when I created another input file, it went wrong. Then I tried for single input file, it was not working though.</p>
  
  <p>Here is my code:</p>
  
  <pre><code>&lt;?php
  $isSubmit=filter_input(INPUT_POST, "submit");
  if(isset($isSubmit){
      echo $_POST["fileToUpload"];
  }
  else {
      echo "not submited";
  }
  
  ?&gt;
  
  &lt;!DOCTYPE html&gt;
  &lt;html&gt;
  &lt;body&gt;
  
  &lt;form action="#" method="post" enctype="multipart/form-data"&gt;
      Select image to upload:
      &lt;input type="file" name="fileToUpload" id="fileToUpload"&gt;
      &lt;input type="submit" value="submit" name="submit"&gt;
  &lt;/form&gt;
  
  &lt;/body&gt;
  &lt;/html&gt; 
  </code></pre>
  
  <p>Now if the <strong>form is submitted</strong>, it goes to else part and display "<strong>not submitted</strong>" on browser. If I load any other page or the same page, the browser says "<strong>localhost is waiting..</strong>"</p>
  
  <p><strong>Then unless I restart the server, the project fails to load.</strong></p>
  
  <p><strong>But when the input type file is changed to text or other, it goes well.</strong></p>
  
  <p>I have looked at <strong>php.ini file</strong> there is no problem with <strong>max file size or file upload or post max file.</strong></p>