Enable Steam Overlay for Steam Purchase problems

If you are unable to make a purchase in Gems of War on Steam try turning on Steam overly. 

1. Go to Steam -> Settings
2. Click the In-Game tab
3. Check "Enable Steam Overlay while in-game" 
4. Go to Library
5. Right-click on Gems of War and select Properties
6. Under the General tab also make sure "Enable Steam Overlay while in-game" is checked