Hearthstone has been updated. Please download the latest version.
Common ProblemsGetting this error when starting Hearthstone
This is caused by your account having been used on a version of Hearthstone that is newer than the version you have on your mobile device. To continue playing, the Hearthstone version on your mobile device needs to update. If the game does not update when opening it on your device, accessing the game on a computer will still be possible until a mobile update is available.