Hello,
Here you may find the latest version of VC plugin – 5.4.3 https://www.8theme.com/download-plugins/ (To update premium plugins, connect to your server using FTP. Copy extracted plugins folders into wp-content/plugins/), also the latest version of xsrote is 4.12, please update theme if it is needed http://xstore.helpscoutdocs.com/article/63-theme-update and then check the problem.
Regards