Yes, ~30 Minutes ago (~18:00 UTC):

  Internal error: Usage credits are required for this model.: {
    "errorKind": "rate_limit"
  }

[Edit] Update from https://status.claude.com/

> We are aware of an issue preventing users from selecting Claude Fable 5 within Claude.ai, Claude Code, and other surfaces, and are working to resolve this issue. Jul 17, 2026 - 18:36 UTC