The RocketCDN integration in WP Rocket attempts to contact the RocketCDN API to validate the pull‑zone. When the request fails, WP Rocket shows the error banner. Failure occurs when the API returns a 5xx status, when the domain is not reachable publicly, or when the request is blocked by a firewall or DNS mis‑configuration.
The plugin then disables CDN rewrites. Assets continue to load from the origin server. No cache clearing removes the banner until the underlying issue is resolved.