Setup: Flutter plugin 2026.7.4 → native iOS SDK 2.6.0. iPhone 16 Pro, iOS
18.7.8, debug build. Production application ID + production access token,
AU merchant.
The reader pairs over Bluetooth, then immediately reports “Reader
Unavailable. Unable to establish a secure connection to Square” and never
reaches Ready. Reproducible across forget/re-pair cycles and app restarts.
If Bluetooth pairing succeeds but the reader fails during the secure connection step, it’s usually an account, token, or provisioning issue rather than Bluetooth. Double-check your production credentials and merchant setup, then collect SDK logs and contact Square support if the issue persists.
Can you ensure you are on the latest version of the SDK? We just shipped a fix for this a few days ago. Mobile SDKs: 2026-07-27 Changelog