Could not find a class file within the tests JAR file while uploading zip file to device farm

I am finding an issue while uploading a zip-with-dependencies.zip file into device farm. It’s giving me a error while upoading. Error goes like this “There was a problem processing your file. We could not find a class file within the tests JAR file. Please unzip your test package and then unjar the tests JAR file, verify that at least one class file is within the JAR file, and try again.” How do I get rid of this error while uploading the file. Is there something wrong in my configuration.

I have tried everything in http://docs.aws.amazon.com/devicefarm/latest/developerguide/troubleshooting-appium-java-testng.html but no luck. Can some body help me with this?