Ayman, you're the best! I can't believe I missed that. It was only set as a user variable not a system variable. Oh well, better pay closer attention next time.

I'd like to hop in as I have the same problem. I see the OP didn't reply, but I have the exact same error message. I've checked, and the simbody-visualizer executable is in the opensim3.3\bin folder (my install directory, which I didn't change after install, is C:\OpenSim3.3). I also verified that O...