Hello Krina,
Thanks for writing in! The version you may have installed in your site is the one with the update notification issues. Please update your X and Cornerstone files manually by uploading the files to your ftp. You can download the latest version from your dashboard here (https://community.theme.co/dashboard/).
Before doing anything, please make sure that you have a backup of your site. To know more how you can update your X and X plugins, please check our our knowledge base here: https://community.theme.co/kb/updating-your-theme-and-plugins/
Hope this helps.