Generating Signed APK play store

Question

I am trying to gerenate signed apk for play store after generating the release folder in messages part of Android Studio it shows a lot of warnings but the apk works without any problem.

You can see the picture of the warning list below:

Answer 1

I'm pretty sure it's caused by proguard that is obfuscating some classes used by this facebook library. You might not see it crash until you use your coded reaches those facebook classes that use those obfuscated classes.

You either add the proguard "dontwarn" rule

-dontwarn javax.annotation.Nullable
-dontwarn javax.annotation.concurrent.GuardedBy
-dontwarn javax.annotation.concurrent.CheckReturnValue
[etc ...]

see what crashes and change with the "keep" rule :

-keep javax.annotation.Nullable
-keep javax.annotation.concurrent.GuardedBy
[etc ...]