Sometimes it’s a temporary issue, but most of the time, it’s either a server-side error or a proper restriction set by the website owners.
Try refreshing the page, this can resolve the issue.
Also make sure the Vurbis servers are whitelisted in the web application firewall.
Tell the customer to whitelist our staging or live IP's on their web application firewall.
live: 104.199.32.34
staging: 104.199.96.14