Hello again, > > When you fire up the Console (typically via "java > sim.display.Console"), one thing it does is try to determine all the > simulation classes in your system. These classes are defined in a > file called sim/display/simulation.classes and are listed by class > name. Console tries to load each of these classes so it can display > them in its list of available simulations. > Anyway, the #1 reason why Java can't find classes referenced by a > simulation class is because it's referring to Java3D stuff and you > don't have Java3D installed. But it's possible that there may be > other reasons. hm, when I explicitly add j3dcore.jar to the build path of my eclipse project, the error disappears. That is good, but strange since it worked without this on my Laptop. And I definitely have java 3d installed because the 3D heatbugs start without problems if I start the console via mason\start\mason.bat. But anyway, I am not really using 3D stuff, so I will ignore this error/bug/warning and get on with my stuff :-) Axel