Hello,
Thanks for using our theme.
Please check – https://prnt.sc/uv8m5g
I can see 6.3.7 version of the theme on your site. If you are using the latest WordPress version, you need to use the latest version of the theme – https://www.8theme.com/documentation/xstore/theme-installation/theme-update/ Clear cache after the update, and you will be able to register the theme.
Regards















