Inside the game's Extras menu, you might've noticed these two options:

Clear Techtree can improve many data-related errors. (Sometimes we update the game without requiring an actual version upgrade through the App Store; you'll need to update the Techtree for the new data to reflect in your account.)

Clear Cache is similar to downloading a fresh copy of the game from the App Store and reinstalling it. This usually requires you to download the assets again and takes a bit longer to complete.