After days debbuing I found a solution.
On the file: /var/www/html/modules/pbxadmin/libs/contentIssabelPBX.php I need to comment the lines (470):
if (isset($_REQUEST['display']) && $_REQUEST['display'] == 'ivr') {
$return_CONFIG_HTML = preg_replace(
'|</tr>\s*(<table .*?</table><img .* id="add_entrie">)\s*<tr>|s',
'</tr><tr><td colspan="2">$1</td></tr><tr>',
$return_CONFIG_HTML);
}