Failed to create thumb image in $_FILES loop - php

Question

I iterate through $_FILES to create thumb images of uploaded pictures. It works fine for the first image but fails for the following pictures. Do I miss to add a special line or there is flow in my code?
Note: Original files gets uploaded successfully and exist in folder before creating thumb out of them.
When I echo error, I get this: "Your server does not support the GD function required to process this type of image.". When I upload it on its own, it works!!!!
Thanks
public function upload_image()
{
$config['upload_path'] = './web/uploads/images/';
$config['allowed_types'] = 'gif|jpg|png';
$config['max_size'] = 5120;
$config['max_width'] = '0';
$config['max_height'] = '0';
$config['encrypt_name'] = true;
$this->load->library('upload');
$this->upload->initialize($config);
foreach ($_FILES as $file => $value)
{
$this->upload->do_upload($file);
$result = $this->upload->data();
if ($this->manipulate_image($result['file_name']) === false)
{
echo 'Failed to create thumb for the image ' . $value['name'] . '<br />';
}
}
}
public function manipulate_image($file_name)
{
$config['image_library'] = 'gd2';
$config['source_image'] = './web/uploads/images/' . $file_name;
$config['create_thumb'] = true;
$config['maintain_ratio'] = false;
$config['width'] = 100;
$config['height'] = 100;
//$config['master_dim'] = 'width';
$config['thumb_marker'] = '_thumb';
$this->load->library('image_lib', $config);
if (! $this->image_lib->resize())
{
$this->image_lib->clear();
return false;
}
$this->image_lib->clear();
return true;
}

Answer 1

I see two things, first, I would move the load on the library outside of the foreach loop then use initialize inside the loop to set the config:
$this->image_lib->initialize($config);
Also, as documented here you can use
echo $this->image_lib->display_errors();
To get more insight on your problem

Answer 2

Apparently loading loading image_lib multiple times in a loop causes this problem.
Solved without including in loop.