After updating the game to version 2.118 on the Android platform, the platform version below 6.0 will no longer be supported. The current technical requirements of the game, as well as the development processes, do not allow using versions below 6.0.
Thank you for understanding!

P.S. Here is a quick guide of how to check your current OS version: 

https://support.google.com/android/answer/7680439?hl=en