Problem should be with this line in utils.php:
$filename = date('YmdHis')."_".osc_sanitize_string($data['name'])."_".preg_replace('/[.,]/', '', $data['i_version']).".zip";
That should be changed into:
$filename = date('YmdHis')."_".osc_sanitize_string($data['name'])."_".preg_replace('/[.,]/', '', (isset($data['s_version']) ? $data['s_version'] : @$data['i_version'])).".zip";
Will be fixed in 4.4 as well