Joomla! 3 frissítéskor ERROR: The archive file is corrupt, truncated or archive parts are missing hiba

class FOFModel extends JModel
{
	protected $table = null;
	protected $otable = null;

	protected $id_list = array();
	protected $id = null;
	protected $record = null;
	protected $list = null;

	protected $pagination = null;
	protected $total = 0;
	
	protected $input = array();

	/**
	 * Returns a new model object. Unless overriden by the $config array, it will
	 * try to automatically populate its state from the request variables.
	 * 
	 * @param string $type
	 * @param string $prefix
	 * @param array $config
	 * @return FOFModel
	 */
	public static function &getAnInstance( $type, $prefix = '', $config = array() )
	{
		$type		= preg_replace('/[^A-Z0-9_\.-]/i', '', $type);
		$modelClass	= $prefix.ucfirst($type);
		$result		= false;