Android release APK crash with java.lang.AssertionError: impossible in java.lang.Enum

Question

I\'ve just built an APK using Gradle for release (ProGuard 4.9 and signed). When I launch the app it crash on this error :

E/AndroidRuntime( 8662): java.lan         


        

Answer 1

You have to tell ProGuard to keep some enum methods.

The Android SDK tools use this ProGuard configuration to achieve it:

# For enumeration classes, see http://proguard.sourceforge.net/manual/examples.html#enumerations
-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

You can either add the above rule to your ProGuard configuration or you can (what I'd prefer) include the default Android rules:

minifyEnabled true
proguardFile getDefaultProguardFile('proguard-android.txt')
proguardFile file('./proguard-project.txt')

Answer 2

Log of my error

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.zonaprop.android, PID: 20337
java.lang.AssertionError: Missing field in 
...
Caused by: java.lang.NoSuchFieldException: 
    at java.lang.Class.getField

The follow answer worked for me https://stackoverflow.com/a/30167048/5279996