[solved] File Upload in CI4 does not work?

Hello,

here is a short snipper from my project:

My View:

PHP Code:

<?= form_open('user/upload_logo'); ?>
                  <input type="file" name="userfile" />
                  <br><p class="text-right">
                  <input type="submit" class="btn btn-primary" value="upload">
                  </p>
<?= form_close(); ?>

And on the Controller's side:  (Just simple to check if getFiles() is working... )

PHP Code:

    public function upload_logo()
    {
        $files = $this->request->getFiles();
        var_dump($files);
    }  


Result is

array(0) { }


Even if I use getFile('userfile') and try validate, move, store, etc. it always returns an error that I am calling a function on null.
So my file is getting lost while uploading

Anyone know how to fix this?

BR,
Niklas