I found the solution!

I edited the file file.php
function save(){
.
.
.

//UPLOAD FILE : Arquivo
if (!$this->_upload('arquivo', &$post, array(
'application/msword' => 'doc',
'application/pdf' => 'pdf',
'application/x-gzip' => 'tar.gz', /*to 'application/x-gzip' => 'gz' */
'application/x-zip' => 'zip' /*'application/zip' => 'zip'*/
)))
return;