Hi Xinu, On Fri, Jul 11, 2008 at 8:14 PM, Xinyu Zhang <xycindy at yahoo.com> wrote: > I tried with 2.4.0 and got a similar problem (see below). I'm afraid I can't see what the problem is from the debug output. Could you get a stack trace. Also try running the viewer single threaded via: osgsimulation --SingleThreaded Robert.