Hi When activated the Cosmos theme, you’ll e inform with a message like this “COSMOS theme recommends/requires the following plugin:” You need to install and activte them by one by. And we’ve checked you mentioned plugin “Viual Composer” itslisted in required plugins.

Could you sen us your wp login info? (you can simply reply this as Private) our support team will take a look for you and install them for you asap.

Regards
ThemeofWP.com Team