How to Fix the "Duplicate Class ListenableFuture" Error in Android If you're working on an Android project and see a build error about a duplicate ListenableFuture class, you've encountered a common dependency conflict. This guide will explain why it happens and show you how to fix it. Understanding the Error The error message looks like this: Duplicate class com.google.common.util.concurrent.ListenableFuture found in modules: guava-23.0.jar (com.google.guava:guava:23.0) and listenablefuture-1.0.jar (com.google.guava:listenablefuture:1.0) This means two different libraries in your project are trying to provide the same class, causing a collision. guava-23.0.jar contains the full Guava library, which includes ListenableFuture . listenablefuture-1.0.jar is a standalone, minimal artifact containing only the ListenableFuture class. The conflict arises when one of your dependencies requires the standalone JAR, but your project also inclu...