That error means that wp-content/themes/xstore/framework/customizer/theme-options/breadcrumbs/breadcrumbs.php file is missing or access is not allowed to that file.
Please try to delete the core plugin and then Install it again from XStore >> Dashboard >> Plugin Installer and check back.
And if the issue will still persists then please try to disable all the third-party plugins (including cache plugins), that does not come bundled with XStore https://xstore.helpscoutdocs.com/article/36-included-plugins , clear the cache of the browser, and check then. Maybe one of the additional plugins is the reason for the problem.
And if the issue will still persists then please remain all the third-party plugins deactivated on your site and provide me the login access to your site in the below-listed format in the private content area and allow permission to debug your site which includes deactivating all the third-party plugins and on-site Customization as well so that I will check and assist you accordingly.
WP Admin URL:
WP Admin Username:
WP Admin Password:
CPanel Admin URL:
CPanel Admin Username:
CPanel Admin Password:
Note: Please take the complete backup of your site first.
Regards 8Themes Team.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.