Please read 'Fixing the problem' to resolve this issue
After updating to 3.4 Pets you may be unable to load any battles: The loading screen will not load the battle after more than 30 seconds even though the bar continues to fill up and empty repeatedly. The spinning Gem wheel will appear in the bottom right-hand corner of the screen.
Fixing the problem
If you're encountering this issue on iOS/Android, you can download the latest fix from the App Store (Google Play or Apple App Stores). We have released a hot-fix that resolves this problem.
Go here to update on IOS
Go here to update on Android