Epic sandbox provider standalone launch — login rejects all test users (FHIR, FHIRTWO)

[vikas tomar]

Hello Everyone,

I'm testing a provider-facing standalone SMART-on-FHIR launch against the Epic public
sandbox (authorization code + PKCE, public client, browser app). I get all the way to the
Epic login screen but EVERY test credential is rejected as "invalid user." It was working
fine on Wednesday, and nothing changed on my end since then.

What's working:
- Authorize request is accepted and issues a ticket, then redirects to the login page.

Where it fails:
- After the login screen loads, every credential I try is rejected.
- The login service (HSWeb_uscdi_1180-1 .../LoginService.svc/AttemptAuthentication) returns:
    "Succeeded": false, "Result": -99,
    "ErrorMessage": "You entered an invalid user ID, password, or other type of
     authentication credential."
- No 2FA is configured (EpicNative2FAShow: false).

Credentials I've tried (all rejected): FHIR/EpicFHIR, USCDI/epicuscdi, argonaut/ARGONAUT, FHIR/EpicFhir11!, FHIRTWO/EpicFhir11!.

I emailed Epic but haven't received a response.

I would really appreciate if someone could help me get it working again.

Thanks,

Thanks,