My application throws a run time exception when trying to broadcast

[pspeed]

You already posted the thread about it in a different thread:

[Solved for now]Serializer locked error. What does it mean? Version jme 3.1

Well, the serializer is locked on purpose when the server starts so that you don’t accidentally add classes after the serializer list has been compiled. …but I stupidly didn’t take into account the case where a client and server run together. But really, Serializer isn’t smart here either as there is no reason to register the same classes twice. I should probably just modify the Serializer to see if the class is already registered before checking the read-only lock. In the mean time, you can…