We are trying to upgrade wordpress via Automatic upgrade plugin but in some hosting server you may get errors like:
Unable to locate WordPress Root directory.
1) Assign required permissions to FTP username and make sure that you are using the correct FTP username and password.
2) Create new FTP account with destination path to the wordpress root directory.
3) Add this code in wp-config.php file of your wordpress blog:
add_filter(’filesystem_method’, create_function(’$a’, ‘return “direct”;’ ));
define( ‘FS_CHMOD_DIR’, 0751 );