I have noticed that this CHOPS3-800 seems to occur when there are difficulties with the internet. The error message I capture in the browser console when this happens is:
Access to fetch at 'https://event.vision.bt.com/vosp_event_recording/web/record' from origin 'https://192.168.1.254' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.
The Google AI explanation given for this is:
Understanding the problem
This console message indicates a Cross-Origin Resource Sharing (CORS) error. Your web application, hosted at https://192.168.1.254, is attempting to make a request to a different origin, https://event.vision.bt.com. By default, browsers enforce a security policy called the "Same-Origin Policy," which prevents a web page from making requests to a different domain than the one that served the web page. CORS is a mechanism that allows servers to explicitly grant permission for cross-origin requests.
The specific error, "Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource," means that your browser first sent an OPTIONS request (a "preflight request") to the server at https://event.vision.bt.com/vosp_event_recording/web/record. This preflight request is sent automatically by the browser to check if the actual request is safe to send. The server's response to this preflight request did not include the Access-Control-Allow-Origin header, which is essential for the browser to determine if it's allowed to proceed with the actual cross-origin request from https://192.168.1.254. Since this header was missing or did not include https://192.168.1.254 as an allowed origin, the browser blocked the request for security reasons.
Suggested fix
The fix for this problem needs to be implemented on the server-side (https://event.vision.bt.com), not on the client-side (https://192.168.1.254). The server needs to be configured to include the Access-Control-Allow-Origin header in its responses to allow requests from your origin.
