If one of your upgrades didn’t finish properly, you most likely had a connectivity error somewhere along the way.

Based on your device’s connection specifications, “Lost Connection Warnings” can take up to a few minutes before turning up in the game.  As a result of the delay, you may continue playing as usual before being notified, however any progress made during this period will not be saved.  

These errors will occur due to a variety of reasons, including but not limited to: poor Internet connection, server issues, ISP errors and/or device performance.

To avoid these issues in the future, I recommend checking our “My game crashes” article via the Help Center.