Connectivity issues are the cause of some problems, including the K4 error.
Following these troubleshooting steps might help minimize the issues:
- Restart the game
- Turn Airplane mode ON, wait 10s and turn it back OFF
- Restart the device
- Make sure you are running the latest version of the Game
- Make sure you are running the latest possible version of your Operating System
- If the issue is happening while on WiFi, check if the same happens in Mobile Data
- If the issue is happening while on Mobile Data, check if the same happens on WiFi
- If it only happens on WiFi, try to restart the Router if you can
- If you can't restart the router, forget the WiFi connection and add it again
If this still doesn't fix the issue, make sure to contact support through the game, in English, and report your location (city and country) so that we can further analyse this.