java.lang.NullPointerException: println needs a message after applying proguard and minify enable true

Question

Works fine in debug mode. But after minify enable true and setting proguard the app crashes with following stacktrace.

 java.lang.NullPointerException: println needs a message
    at android.util.Log.println_native(Native Method)
    at android.util.Log.d(Log.java:160)
    at l9.d$b.d(SourceFile:211)
    at l9.d$b.onSuccess(SourceFile:208)
    at io.reactivex.internal.operators.single.SingleObserveOn$ObserveOnSingleObserver.run(SourceFile:81)
    at id.b$b.run(SourceFile:109)
    at android.os.Handler.handleCallback(Handler.java:942)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loopOnce(Looper.java:201)
    at android.os.Looper.loop(Looper.java:288)
    at android.app.ActivityThread.main(ActivityThread.java:7898)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:936)

I have tried Removing all the Log. functions. Putting try catch on Log functions. Used following proguard rules

    -assumenosideeffects class java.io.PrintStream {
     public void println(%);
     public void println(**);
 }

-assumenosideeffects class android.util.Log {
    public static *** d(...);
}

But nothing works and the issue persists. Same issue persists in release build with minify enable and proguard.