The following solution is only for CS-Cart 4.1.5 users who upgraded their Twigmo add-ons to version 3.4 before June 2, 2014.
1) Download the TwigmoUpgrade.php file attached to this article to your local computer;
2) Upload the downloaded file to the /app/addons/twigmo/Twigmo/Upgrade/ directory of your CS-Cart 4.1.5 installation overwriting the existing file;
3) Follow the instructions to upgrade your Twigmo add-on to version 3.5. in the automated way.