Hello, I have tried to start the example master / slave: coevolve1, run single computer. I have set the following lines in the coevolve1.master.params and coevolve1.slave.params: verbosity = 0 eval.compression = false However I experienced problems by starting the coevolve1 master/slave. Here is the printout: - Master response: Threads: breed/1 eval/1 Seed: -241285081 Job: 0 Setting up Initializing Generation 0 Slave /127.0.0.1/1296838850404 connected successfully. Slave(/127.0.0.1/1296838850404) Slave is shutting down.... - Slave response: ... reading next problem Read problem: 2 Exception in thread "MainThread: " java.lang.NullPointerException at ec.eval.MasterProblem.evaluate(MasterProblem.java:267) at ec.eval.Slave.evaluateGroupedProblemForm(Slave.java:639) at ec.eval.Slave.main(Slave.java:457) - Also since there are going to be some changes around coevolve stuff, are there any changes also planned to be added to the master/slave ? Nikola