You are using the latest version of XStore Core plugin but the version of the theme is old http://prntscr.com/r7xmg8
To avoid difficulties, backup the theme files and database before any update.
You can create a staging site (full copy of the existing one) and do updates there first. If everything is ok then you’ll be able to update the production site https://xstore.helpscoutdocs.com/article/63-theme-update
