Warning: Exception while processing task java.io.IOException: java.lang.IllegalArgumentException: Can't find common super class of [com/google/android/gms/internal/measurement/zzkf] (with 1 known super classes) and [com/google/android/gms/internal/measurement/zzko] (with 1 known super classes)
My proguard rules:
-keep class com.google.android.** { *; }
-dontwarn com.google.android.**
A possible reason might be the use of different Play Service library versions. Make sure you are using the same version for all included libraries.
implementation 'com.google.android.gms:play-services-analytics:16.0.1'
implementation 'com.google.android.gms:play-services-auth:11.8.0' // should be the same version
Some versions have incompatible APIs and implementations, causing conflicts that are detected by proguard. Ignoring them might cause crashes at runtime instead.
If you are already using the same version everywhere, it may be one of your third-party dependencies, that includes another version of the Play Services internally.
