Check if your game is updated to latest version, if it is and still you keep getting this error than follow the Steps below:-
Step 1 : Remove the hack from Cydia.
Step 2 : Then delete the game. (Make sure you backup your game progress on Game Center).
Step 3 : Do fully cache clear by using "icleaner"
Step 4 : Respiring or Restart the device.
Step 5 : Install the game from App Store.
Step 6 : Then do not open the game, first install the hack by using ifile or filza
Step 7 : Now turn on the hack from the settings, open the game and get your account from the backup.
You'll have it back working.
It has already been mentioned at the beginning of the thread, you cannot use crowns to speed up or instant build any kind of buildings. And if you do, the error you mentioned will pop-up.
Max Crown you can use to speed up building is 5.