Symptoms

The Manual Review page appears to be frozen upon opening, the throbber is spinning infinitely. The following error appears in the browser console:

WebSocket connection to 'wss://vantage-**.abbyy.com/verification/manualreview/***/notifications' failed

Cause

WSS protocol which usually operates over the default ports of 80 and 443, is somehow blocked on a client's side.

Resolution

Please make sure that no Firewall, VPN, or Proxy is blocking the WSS protocol, and that ports 80 and 443 are open.