Cropped image encrypted data not post in codeigniter on live server. Why? - codeigniter

Question

I have a situation where a user select photo and cropped it.After cropping encoded data passed to hidden input has successfully but when posting my form the image data not post.Only blank page shown.
Same code are working fine on local server. But on live server this happened to me.
Let me share my code. Please guide me where i am doing wrong.
$(".gambar").attr("src", "<?php echo base_url().'assets/img/users/defualt.jpg");
var $uploadCrop,
tempFilename,
rawImg,
imageId;
function readFile(input) {
if (input.files && input.files[0]) {
var reader = new FileReader();
reader.onload = function (e) {
$('.upload-demo').addClass('ready');
$('#cropImagePop').modal('show');
rawImg = e.target.result;
}
reader.readAsDataURL(input.files[0]);
}
else {
swal("Sorry - you're browser doesn't support the FileReader API");
}
}
$uploadCrop = $('#upload-demo').croppie({
viewport: {
width: 150,
height: 150,
type: 'circle'
},
boundary: {
width: 265,
height: 265
},
enforceBoundary: false,
enableExif: true,
enableOrientation: true,
orientation: 4,
});
$('#cropImagePop').on('shown.bs.modal', function(){
$uploadCrop.croppie('bind', {
url: rawImg
}).then(function(){
});
});
$('.item-img').on('change', function () {
imageId = $(this).data('id');
tempFilename = $(this).val();
$('#cancelCropBtn').data('id', imageId);
readFile(this); });
$('#cropImageBtn').on('click', function (ev) {
$uploadCrop.croppie('result', {
type: 'canvas',
format: 'jpeg',
size: {width: 150, height: 150}
}).then(function (resp) {
$('#imageEncoder').val(resp);
$('#item-img-output').attr('src', resp);
$('#cropImagePop').modal('hide');
$('#profile_form').submit();
});
});
<form action="<?= base_url().'userController/update_staff_picture' ?>" method="post" enctype="multipart/form-data" id="profile_form">
<input type="hidden" name="imageEncoder" id="imageEncoder">
<label class="cabinet center-block">
<figure>
<img src="" class="gambar img-responsive img-thumbnail img-circle" id="item-img-output" />
<figcaption><i class="fa fa-camera"></i></figcaption>
</figure>
<input type="file" class="item-img file center-block" name="file_photo"/>
</label>
</form>
User Controller
public function update_staff_picture(){
$data = $this->input->post('imageEncoder');
echo "<pre>";
print_r($data);
exit();
list($type, $data) = explode(';', $data);
list(, $data) = explode(',', $data);
$data = base64_decode($data);
$image_name = date('ymdgis').'.png';
$req['image']=$image_name;
file_put_contents('./assets/img/users/'.$image_name, $data);
$this->db->set($req);
$this->db->where('userID',$userID);
$this->db->update('users');
redirect(base_url().'staff-profile/'.$_POST['userID']);
}