Go to Appearance > Themes > install and activate Storefront theme – official WC theme and check if you have this issue with our theme only or even with official theme too.
Could you please provide wp-admin access in Private Content so we could check the problem?
We’ll be able to help you only in case problem appears with our theme only and works fine with Storefront.
Please update Ultimate Addons for Visual Composer to 3.16.10 and Visual Composer.
To update plugins, connect to your server using FTP. Copy extracted plugins folders into wp-content/plugins/ . The latest versions of plugins you can find here https://www.8theme.com/download-plugins/page/2/.
Then try to disable 3-rd party plugins (means the plugins that are not included in the theme package are not in the list of required plugins) and check issues.