Usual advice. Scan your Orbiter directories for empty files (0 bytes). If you find any, trash your Orbiter installation and
reinstall (redownload if you have to). Install OrbiterSound 3 first, then the DG3 and NO other addons. Test to see if it
still crashes. If it does, review the scenario files to see what meshes are being called for, and see if they are there.
Chances are a ship is missing or a texture is missing.