What is wrong with my Android Proguard rule I am using the Gson android library for handling data with a kotlin data class. Kotlin Data Class class DataType { data class UserData { var userName: String = ""; var userEmail: String = ""; } } Android Proguard Rule -keep class .DataType.* {*;} The problem is my application working fine in debug mode, but proguard obfuscated the code in release mode and the release version not working as expected. Any solution???