Install PECL UploadProgress
If you want to enable the cool Progress Tracking feature, you need to get PECL UploadProgess extension installed. More information about this extension you may find here. Lastly, please try to have PHP version 5.2.x

If you are use Linux, do as follow:

  1. Run the following command:
    pecl install uploadprogress

  2. Open your php.ini and register the extension:

  3. Restart server.

If you are use Window, do as follow:

  1. Download this php_uploadprogress.dll

  2. Copy php_uploadprogress.dll into {PHP_PATH}\ext folder

  3. Open php.ini and add the following:

  4. Restart server.