Homebrew recently updated my machine's protoc to 2.5.0 during an upgrade. The new generated .java files in my module require protobuf-java version 2.5.0 because they reference a new interface com.google.protobuf.Parser. I had a second module that used the first module with the protobuf classes, but also uses akka-remote. Maven decided to prefer akka-remote's dependency and my build failed.

I suspect others will stumble upon this problem too, so I recommend bumping the dependency in akka to protobuf 2.5.0.