Hi there! I understand that your Vita Mahjong app won’t open on your Android device, and you’re worried about missing out on the Valentine’s puzzle tournament. Let’s see if we can get it working again for you quickly.

First, just to make sure I have the full picture, could you tell me:
- Does the app show any error message or does it just not launch at all?
- Have you tried anything already, such as restarting your device or clearing app data?
- Also, is your device connected to the internet when you try to open the app?

In the meantime, here’s a step-by-step guide to troubleshoot the app not opening on your Android 10 device with WebKit:

1. Restart your phone
Sometimes a simple restart clears temporary glitches affecting apps.

2. Clear app cache
- Go to your device’s Settings
- Tap Apps & notifications (or just Apps)
- Find and select Vita Mahjong
- Tap Storage & cache
- Tap Clear cache
This only removes temporary files and won’t delete your game data.

3. Clear app data (if cache clearing doesn’t work)
- Following the steps above, instead of just clearing cache, try Clear storage or Clear data.
Note: This will reset app settings and may remove locally saved progress, so confirm if you are logged in or if your progress syncs online.

4. Check for app updates
- Open the Google Play Store
- Search for Vita Mahjong
- If there is an Update button, tap it to install the latest version.

5. Ensure the app has required permissions
- In the App info screen (where you cleared cache), tap Permissions
- Make sure necessary permissions like storage or network access are enabled.

6. Reinstall the app
- If the app still doesn’t open, try uninstalling and reinstalling it from the Play Store.
Be aware you might lose local game data unless it’s backed up online.

7. Check for system updates
- Go to Settings > System > Advanced > System update to see if there is an Android update pending that might improve compatibility.

If after trying these steps it still won’t open, there could be a specific issue with the app version or your device’s compatibility. In that case, I can help gather more technical details or escalate the problem to our development team.

Would you like me to walk you through any of the above steps in more detail? And please let me know what you’ve tried so far!

Are you satisfied with this approach so far?