A. 1. Check your internet connection to ensure you are connected to Wi-Fi or mobile data. 2. Ensure you are entering the correct username and password. If you have forgotten your password, use the 'Forgot Password' option to reset it. 3. Clear the app cache by going to Settings > Apps > BigFuture > Storage > Clear Cache. 4. Restart your device and try logging in again.

B. If the issue persists, uninstall the app and reinstall it from the Google Play Store. This can resolve any corrupted files that may be causing the login issue.