Hi all,
I’m facing a device-specific issue in a live production iOS app distributed privately via the App Store . The app crashes immediately after login on one client’s iPhone, while the same account works fine on other devices. There’s no crash log generated in Analytics, and the app just pops to the home screen.
Environment:
App: Production app on App Store iOS version: 26.3 Devices: Only one device exhibits the crash; other iPhones work fine Login flow: App calls an API and writes the response to a local SQLite database immediately after login Distribution: App Store (Privately). The user is install via the redemption codes.
Observations:
- All users on the problematic device crash immediately after login.
- The crash does not occur on any other devices, including the same iOS version.
- The client had already uninstalled and reinstalled the app via App Store cloud download, but the crash persisted.
- No crash log appears in Analytics or Xcode (process just terminates).
- Device restart had not been attempted before reinstall.
- App does not use Keychain tokens; local DB is only SQLite in the app sandbox.
Hypotheses so far:
- Corrupted binary or cached app installation on that device
- SQLite database corruption or write failure
- Device-specific OS/environment issue (temp files, file locks, provisioning)
- iOS watchdog silently terminating the app during post-login DB write
- Language / region differences unlikely
Questions:
- Is it possible for a device to retain a corrupted app binary or cached installation even after uninstall + cloud download reinstall from the App Store?
- Can uninstalling, restarting the device, and reinstalling guarantee a fresh binary and sandbox?
- Are there any known iOS behaviors where a local SQLite write could trigger an instant crash on one device only, without generating crash logs?
- Any other suggestions for diagnosing this device-specific post-login crash in a live production environment?
Thanks in advance for any guidance — this issue is affecting a client’s live usage, and we’d like to understand the root cause and best way to resolve it safely.