When I load a page with video the admin checker displays “Admin: Checking the video file… then fails with message “Admin: Check failed.”
Firefox console shows error: “Request from an extraneous source is blocked: A single source policy prohibits reading a remote resource at https://video-checker.foliovision.com/. (Reason: Failed to execute CORS request).” with reference to doc https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS/Errors/CORSDidNotSucceed.
Chrome console shows error: POST https://video-checker.foliovision.com/ net::ERR_CONNECTION_REFUSED jquery.js?ver=1.12.4-wp:4
If I understand correctly, in order for the Admin checker start working my site https://gnm-practice.ru needs to be added to the CORS policy at video-checker.foliovision.com.