A. 1. Force stop the app: Go to Settings > Apps > LEGO > Force Stop. Then reopen the app to see if it resolves the black screen issue. 2. Check for app updates: Open the Google Play Store, search for LEGO, and update if necessary. 3. Reboot your device: Restarting can clear temporary glitches that may cause a black screen.

B. 4. Uninstall and reinstall the app: This can help if the app files are corrupted. Go to Settings > Apps > LEGO > Uninstall, then reinstall from the Google Play Store.