Before taking any other steps, make sure that your game is updated and that the device you’re playing on is of the minimum specification needed to run the game smoothly. A full list of supported devices can be found below, under the article heading ‘What devices are compatible with Rivengard?’.
If you’ve checked the list and the device is of minimum specification and up-to-date, the next best step is to restart your device, which clears the memory. (And - don’t worry - this will not cause any loss of data).
Make sure you’ve recently connected your game to Game Center or Google Play Games to synchronise your progress before reinstalling the game.
If you can reproduce a crash with a specific set of actions in the game, please get in contact with us.