Crossplattform Networking with Unity Server and C++ Client and Android(Java) Client

Hey, we are trying to build a server in Unity with the code from the unity - manual . With this server we want to connect clients that are written in c++ and java. (only local) The problem is: Unity Server accepts Unity clients and c++-server accepts c++-clients but it doesnt work together. We try to build the c++-client with the Raknet - Networking - Engine because we want to use unity's hlapi. Maybe someone has an idea why it doesnt work. thx for your ideas. By Seva