CHW-3703 SAMLIdentityProviderUnreachable

the SAML identity provider's metadata endpoint could not be fetched or parsed; verify the IdP metadata URL is reachable and returns well-formed EntityDescriptor XML, then retry

Default message: the SAML identity provider’s metadata endpoint could not be fetched or parsed; verify the IdP metadata URL is reachable and returns well-formed EntityDescriptor XML, then retry
HTTP status: 502 (server)

Problem. A SAML admin endpoint (/init, /acs, /metadata) returned 502 because the IdP metadata could not be fetched or parsed. Cause. The IdP metadata URL was unreachable (DNS / firewall / timeout), the IdP returned a 5xx, or the XML returned was not a valid EntityDescriptor. Split out from CHW-5711 so operators can tell an IdP-side outage apart from an SP-config problem. Fix. Verify the IdP metadata URL from the Chainsaw host, retry after the IdP stabilises, or paste a fresh metadata XML snapshot via the SSO admin UI if the IdP no longer exposes a metadata endpoint. HTTP 502.