Hello all, There seems to be a problem with making checkpoints in simulations with the current version in the CVS-repo. I attached the stacktrace (taken from trying to make a checkpoint when running the HeatBugs3D demo). It's just a java.io.NotSerializableException that pops up. But the trace doesn't really show much more usable info to track the problem down. Any ideas where it might go wrong? greetings Bruno -- Bruno Van Den Bossche [log in to unmask] http://www.ibcn.intec.UGent.be