Hi there! It seems like you're encountering an "Internal Error" while playing Bubble Cash after the tutorial level. Let’s work together to resolve this.

First, can you let me know if you've tried any troubleshooting steps already? Here are a few things we can start with:

1. Restart the App: Sometimes, just closing the app completely and reopening it can resolve internal errors.

2. Check for Updates: Make sure your Bubble Cash app is updated to the latest version. You can do this by going to the App Store, searching for Bubble Cash, and tapping "Update" if it appears.

3. Clear Cache and Data: On your iPhone, you don’t have a direct "clear cache" option like on Android, but you can try uninstalling and reinstalling the app. This can refresh the app and clear any potentially corrupted data.

4. Check your Internet Connection: Make sure your internet connection is stable. You can try switching between Wi-Fi and mobile data if possible to see if that helps.

5. Device Compatibility: Lastly, ensure that your iOS version (18.0) is compatible with the latest version of the Bubble Cash app by checking the App Store description.

If you’ve already tried these steps, let me know, and we can dive a little deeper to investigate any account or server issues that may be causing this error. Are you satisfied with the solutions I've provided so far?