If I create a submenu I get the following error message

Notice: Undefined offset: 1 in /var/www/clients/client1/web7/web/modules/mod_omgmenu/helper.php on line 199
Notice: Trying to get property of non-object in /var/www/clients/client1/web7/web/modules/mod_omgmenu/helper.php on line 199
Warning: Creating default object from empty value in /var/www/clients/client1/web7/web/modules/mod_omgmenu/helper.php on line 199
Notice: Undefined property: stdClass::$params in /var/www/clients/client1/web7/web/modules/mod_omgmenu/helper.php on line 204
Fatal error: Call to a member function get() on null in /var/www/clients/client1/web7/web/modules/mod_omgmenu/helper.php on line 204

PHP5.6.30
Joomla 3.7.1

How can I fix this bug?

Hello, thanks for using our extension!

Maybe you using old version, could you please download latest version and reinstall: www.omegatheme.com/joomla/extensions/315-omg-menu

Regards,
Kien