I just got similar problem in my java application. After I change the outer class method from "private" to "protected" or "public" (or just remove "private"), it is ok. (However, if I change your example's getString() to "protected", the problem still exists.) I am also using Java 11 and proguard 6.1.1.
I just got similar problem in my java application. After I change the outer class method from "private" to "protected" or "public" (or just remove "private"), it is ok. I am also using Java 11 and proguard 6.1.1.