A. If the app becomes unusable after an update, try clearing the app's cache and data. Go to 'Settings' > 'Apps' > 'RFI Pure Radio' > 'Storage' > 'Clear Cache' and then 'Clear Data'. This will reset the app to its original state without losing your personal settings. After this, restart the app and see if it functions properly.

B. If clearing the cache and data does not resolve the issue, consider uninstalling the app and then reinstalling it from the Google Play Store. This can help eliminate any corrupted files that may have been introduced during the update.