A. To address lagging and unexpected closures, start by clearing the app's cache. Go to 'Settings' > 'Apps' > 'Facemoji AI Emoji Keyboard' > 'Storage' > 'Clear Cache'. This can help improve performance by removing temporary files that may be causing issues.

B. If the problem persists, consider uninstalling and reinstalling the app. This can resolve any corrupted files that may be causing the app to crash. To do this, go to 'Settings' > 'Apps' > 'Facemoji AI Emoji Keyboard' > 'Uninstall', then download it again from the Google Play Store.