A. 1. Verify your login credentials: Ensure you are entering the correct username and password. If you have forgotten your password, use the 'Forgot Password' feature to reset it. 2. Check your internet connection: Ensure you have a stable internet connection, as connectivity issues can lead to unauthorized access errors.

B. 3. Clear app data: Go to Settings > General > iPhone Storage, find SmartLinx Go, and select 'Offload App'. This can help clear any corrupted data causing the error.